diff --git a/Piwik.Tracker.Samples/Piwik.Tracker.Samples.csproj b/Piwik.Tracker.Samples/Piwik.Tracker.Samples.csproj
index 25b8432..11a6a85 100644
--- a/Piwik.Tracker.Samples/Piwik.Tracker.Samples.csproj
+++ b/Piwik.Tracker.Samples/Piwik.Tracker.Samples.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">x86</Platform>
@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Piwik.Tracker.Samples</RootNamespace>
     <AssemblyName>Piwik.Tracker.Samples</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <FileAlignment>512</FileAlignment>
@@ -39,6 +39,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|x86' ">
     <PlatformTarget>x86</PlatformTarget>
@@ -48,6 +49,7 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'">
     <DebugSymbols>true</DebugSymbols>
@@ -57,6 +59,7 @@
     <PlatformTarget>AnyCPU</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'">
     <OutputPath>bin\Release\</OutputPath>
@@ -66,10 +69,12 @@
     <PlatformTarget>AnyCPU</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Net.Http" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
diff --git a/Piwik.Tracker.Samples/PiwikTrackerSamples.cs b/Piwik.Tracker.Samples/PiwikTrackerSamples.cs
index 9a72789..3f55b19 100644
--- a/Piwik.Tracker.Samples/PiwikTrackerSamples.cs
+++ b/Piwik.Tracker.Samples/PiwikTrackerSamples.cs
@@ -1,17 +1,16 @@
-using System;
-using System.Text;
-using System.Net;
-using System.IO;
-
-namespace Piwik.Tracker.Samples
+namespace Piwik.Tracker.Samples
 {
+    using System;
     using System.Collections.Generic;
+    using System.Net.Http;
+    using System.Threading.Tasks;
 
     internal class PiwikTrackerSamples
     {
         private const string UA = "Firefox";
         private static readonly string PiwikBaseUrl = "http://piwik.local";
         private static readonly int SiteId = 1;
+        private static readonly HttpClient HttpClient = new HttpClient();
 
         private static void Main(string[] args)
         {
@@ -60,12 +59,12 @@ private static void Main(string[] args)
         /// <summary>
         /// Triggers a Goal conversion
         /// </summary>
-        static private void GoalConversion()
+        private static async Task GoalConversionAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackGoal(1, 42.69F);
+            var response = await piwikTracker.TrackGoalAsync(1, 42.69F);
 
             DisplayDebugInfo(response);
         }
@@ -73,9 +72,9 @@ static private void GoalConversion()
         /// <summary>
         /// Records 2 page scoped custom variables and 2 visit scoped custom variables
         /// </summary>
-        static private void RecordCustomVariables()
+        private static async Task RecordCustomVariablesAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetCustomVariable(1, "var1", "value1");
@@ -84,7 +83,7 @@ static private void RecordCustomVariables()
             piwikTracker.SetCustomVariable(1, "pagevar1", "pagevalue1", Scopes.Page);
             piwikTracker.SetCustomVariable(2, "pagevar2", "pagevalue2", Scopes.Page);
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -92,15 +91,15 @@ static private void RecordCustomVariables()
         /// <summary>
         /// Records 2 custom dimensions
         /// </summary>
-        static private void RecordCustomDimensions()
+        private static async Task RecordCustomDimensionsAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetCustomTrackingParameter("dimension1", "value1");
             piwikTracker.SetCustomTrackingParameter("dimension2", "value2");
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -108,12 +107,12 @@ static private void RecordCustomDimensions()
         /// <summary>
         ///  Records a simple page view with a specified document title
         /// </summary>
-        static private void RecordSimplePageView()
+        private static async Task RecordSimplePageViewAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -121,9 +120,9 @@ static private void RecordSimplePageView()
         /// <summary>
         /// Records a simple page view with advanced user, browser and server properties
         /// </summary>
-        static private void RecordSimplePageViewWithCustomProperties()
+        private static async Task RecordSimplePageViewWithCustomPropertiesAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetResolution(1600, 1400);
@@ -148,7 +147,7 @@ static private void RecordSimplePageViewWithCustomProperties()
             piwikTracker.SetUrl("http://piwik-1.5/supernova");
             piwikTracker.SetUrlReferrer("http://supernovadirectory.org");
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -156,9 +155,9 @@ static private void RecordSimplePageViewWithCustomProperties()
         /// <summary>
         /// Records a simple page view with custom geo location parameters
         /// </summary>
-        static private void RecordSimplePageViewWithCustomGeoLocation()
+        private static async Task RecordSimplePageViewWithCustomGeoLocationAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetTokenAuth("XYZ");
 
             piwikTracker.SetUserAgent(UA);
@@ -169,7 +168,7 @@ static private void RecordSimplePageViewWithCustomGeoLocation()
             piwikTracker.SetLatitude(48.2F);
             piwikTracker.SetLongitude(2.1F);
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -177,14 +176,14 @@ static private void RecordSimplePageViewWithCustomGeoLocation()
         /// <summary>
         /// Records a simple page view with generation time metric
         /// </summary>
-        static private void RecordSimplePageViewWithGenerationTime()
+        private static async Task RecordSimplePageViewWithGenerationTimeAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetGenerationTime(10000);
 
-            var response = piwikTracker.DoTrackPageView("Document title of current page view");
+            var response = await piwikTracker.TrackPageViewAsync("Document title of current page view");
 
             DisplayDebugInfo(response);
         }
@@ -192,9 +191,9 @@ static private void RecordSimplePageViewWithGenerationTime()
         /// <summary>
         /// Triggers a Goal conversion with advanced attribution properties
         /// </summary>
-        static private void GoalConversionWithAttributionInfo()
+        private static async Task GoalConversionWithAttributionInfoAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             var attributionInfo = new AttributionInfo();
@@ -206,7 +205,7 @@ static private void GoalConversionWithAttributionInfo()
 
             piwikTracker.SetAttributionInfo(attributionInfo);
 
-            var response = piwikTracker.DoTrackGoal(1, 42.69F);
+            var response = await piwikTracker.TrackGoalAsync(1, 42.69F);
 
             DisplayDebugInfo(response);
         }
@@ -214,12 +213,12 @@ static private void GoalConversionWithAttributionInfo()
         /// <summary>
         /// Records a clicked link
         /// </summary>
-        static private void TrackLink()
+        private static async Task TrackLinkAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackAction("http://dev.piwik.org/svn", ActionType.Link);
+            var response = await piwikTracker.TrackActionAsync("http://dev.piwik.org/svn", ActionType.Link);
 
             DisplayDebugInfo(response);
         }
@@ -227,12 +226,12 @@ static private void TrackLink()
         /// <summary>
         /// Records a file download
         /// </summary>
-        static private void TrackDownload()
+        private static async Task TrackDownloadAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackAction("http://piwik.org/path/again/latest.zip", ActionType.Download);
+            var response = await piwikTracker.TrackActionAsync("http://piwik.org/path/again/latest.zip", ActionType.Download);
 
             DisplayDebugInfo(response);
         }
@@ -240,50 +239,50 @@ static private void TrackDownload()
         /// <summary>
         /// Records a category page view
         /// </summary>
-        static private void ECommerceCategoryView()
+        private static async Task ECommerceCategoryViewAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetEcommerceView("", "", new List<string> { "Electronics & Cameras" });
-            var response = piwikTracker.DoTrackPageView("Looking at Electronics & Cameras page with a page level custom variable");
+            var response = await piwikTracker.TrackPageViewAsync("Looking at Electronics & Cameras page with a page level custom variable");
             DisplayDebugInfo(response);
         }
 
         /// <summary>
         /// Records a product view
         /// </summary>
-        static private void ECommerceView()
+        private static async Task ECommerceViewAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetEcommerceView("SKU2", "PRODUCT name", new List<string> { "Electronics & Cameras", "Clothes" });
 
-            var response = piwikTracker.DoTrackPageView("incredible title!");
+            var response = await piwikTracker.TrackPageViewAsync("incredible title!");
             DisplayDebugInfo(response);
         }
 
         /// <summary>
         /// Records a product view which doesn't belong to a category
         /// </summary>
-        static private void ECommerceViewWithoutCategory()
+        private static async Task ECommerceViewWithoutCategoryAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.SetEcommerceView("SKU VERY nice indeed", "PRODUCT name");
 
-            var response = piwikTracker.DoTrackPageView("another incredible title!");
+            var response = await piwikTracker.TrackPageViewAsync("another incredible title!");
             DisplayDebugInfo(response);
         }
 
         /// <summary>
         /// Update an eCommerce Cart with one product
         /// </summary>
-        static private void UpdateECommerceCartWithOneProduct()
+        private static async Task UpdateECommerceCartWithOneProductAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.AddEcommerceItem(
@@ -293,7 +292,7 @@ static private void UpdateECommerceCartWithOneProduct()
                 2
             );
 
-            var response = piwikTracker.DoTrackEcommerceCartUpdate(1000.4);
+            var response = await piwikTracker.TrackEcommerceCartUpdateAsync(1000.4);
 
             DisplayDebugInfo(response);
         }
@@ -301,25 +300,25 @@ static private void UpdateECommerceCartWithOneProduct()
         /// <summary>
         /// Update an eCommerce Cart with one product
         /// </summary>
-        static private void UpdateECommerceCartWithOneProductSKUOnly()
+        private static async Task UpdateECommerceCartWithOneProductSKUOnlyAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.AddEcommerceItem(
                 "SKU VERY nice indeed"
             );
 
-            var response = piwikTracker.DoTrackEcommerceCartUpdate(1000.2);
+            var response = await piwikTracker.TrackEcommerceCartUpdateAsync(1000.2);
             DisplayDebugInfo(response);
         }
 
         /// <summary>
         /// Update an eCommerce Cart with multiple products
         /// </summary>
-        static private void UpdateECommerceCartWithMultipleProducts()
+        private static async Task UpdateECommerceCartWithMultipleProductsAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.AddEcommerceItem(
@@ -346,7 +345,7 @@ static private void UpdateECommerceCartWithMultipleProducts()
                 20
             );
 
-            var response = piwikTracker.DoTrackEcommerceCartUpdate(1000);
+            var response = await piwikTracker.TrackEcommerceCartUpdateAsync(1000);
 
             DisplayDebugInfo(response);
         }
@@ -354,9 +353,9 @@ static private void UpdateECommerceCartWithMultipleProducts()
         /// <summary>
         /// Registers 2 eCommerce orders
         /// </summary>
-        static private void RecordTwoECommerceOrders()
+        private static async Task RecordTwoECommerceOrdersAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             // First order
@@ -378,7 +377,7 @@ static private void RecordTwoECommerceOrders()
             );
 
             var response =
-                piwikTracker.DoTrackEcommerceOrder(
+                await piwikTracker.TrackEcommerceOrderAsync(
                     "137nsjusG 1094",
                     1111.11,
                     1000,
@@ -399,7 +398,7 @@ static private void RecordTwoECommerceOrders()
                 1
             );
 
-            response = piwikTracker.DoTrackEcommerceOrder(
+            response = await piwikTracker.TrackEcommerceOrderAsync(
                 "1037Bjusu4s3894",
                 2000,
                 1500,
@@ -411,9 +410,9 @@ static private void RecordTwoECommerceOrders()
             DisplayDebugInfo(response);
         }
 
-        static private void RecordECommerceOrder()
+        private static async Task RecordECommerceOrderAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
             piwikTracker.AddEcommerceItem(
@@ -433,7 +432,7 @@ static private void RecordECommerceOrder()
             );
 
             var response =
-                piwikTracker.DoTrackEcommerceOrder(
+                await piwikTracker.TrackEcommerceOrderAsync(
                     "133nsjusu 1094",
                     1111.11,
                     1000,
@@ -445,42 +444,42 @@ static private void RecordECommerceOrder()
             DisplayDebugInfo(response);
         }
 
-        private static void BulkTrackTwoRequests()
+        private static async Task BulkTrackTwoRequestsAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
 
             piwikTracker.SetUserAgent(UA);
             piwikTracker.SetTokenAuth("YOUR TOKEN");
 
             piwikTracker.EnableBulkTracking();
 
-            piwikTracker.DoTrackPageView("Tracking Request 1");
-            piwikTracker.DoTrackPageView("Tracking Request 2");
+            await piwikTracker.TrackPageViewAsync("Tracking Request 1");
+            await piwikTracker.TrackPageViewAsync("Tracking Request 2");
 
-            DisplayDebugInfo(piwikTracker.DoBulkTrack());
+            DisplayDebugInfo(await piwikTracker.BulkTrackAsync());
         }
 
-        static private void TrackSiteSearch()
+        private static async Task TrackSiteSearchAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackSiteSearch("keyword1", "category2", 0);
+            var response = await piwikTracker.TrackSiteSearchAsync("keyword1", "category2", 0);
 
             DisplayDebugInfo(response);
         }
 
-        static private void TrackSongPlayback()
+        private static async Task TrackSongPlaybackAsync()
         {
-            var piwikTracker = new PiwikTracker(SiteId, PiwikBaseUrl);
+            var piwikTracker = new PiwikTracker(HttpClient, SiteId, PiwikBaseUrl);
             piwikTracker.SetUserAgent(UA);
 
-            var response = piwikTracker.DoTrackEvent("music", "play", "Eye Of The Tiger");
+            var response = await piwikTracker.TrackEventAsync("music", "play", "Eye Of The Tiger");
 
             DisplayDebugInfo(response);
         }
 
-        static private void DisplayDebugInfo(TrackingResponse response)
+        private static void DisplayDebugInfo(TrackingResponse response)
         {
             Console.WriteLine("DEBUG_LAST_REQUESTED_URL :");
             Console.WriteLine(response.RequestedUrl);
diff --git a/Piwik.Tracker.Samples/app.config b/Piwik.Tracker.Samples/app.config
index cb2586b..b7a7ef1 100644
--- a/Piwik.Tracker.Samples/app.config
+++ b/Piwik.Tracker.Samples/app.config
@@ -1,3 +1,3 @@
 <?xml version="1.0"?>
 <configuration>
-<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/></startup></configuration>
+<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/></startup></configuration>
diff --git a/Piwik.Tracker.Tests/PiwikTrackerWithMockedServerTests.cs b/Piwik.Tracker.Tests/PiwikTrackerWithMockedServerTests.cs
index eb83c91..ee1dc65 100644
--- a/Piwik.Tracker.Tests/PiwikTrackerWithMockedServerTests.cs
+++ b/Piwik.Tracker.Tests/PiwikTrackerWithMockedServerTests.cs
@@ -57,12 +57,12 @@ public void SetUpTest()
         [Test]
         [TestCase("myPage")]
         [TestCase("myPage/?Ü&")]
-        public void DoTrackPageView_Test(string documentTitle)
+        public async Task TrackPageView_Test(string documentTitle)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
             //Act
-            var actual = _sut.DoTrackPageView(documentTitle);
+            var actual = await _sut.TrackPageViewAsync(documentTitle);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -79,7 +79,7 @@ public void DoTrackPageView_Test(string documentTitle)
         [TestCase("myCategory", "myAction", "myName", "myValue")]
         [TestCase("myCategory", "myAction", "myName", "")]
         [TestCase("myCategory", "myAction", "", "myValue")]
-        public void DoTrackEvent_Test(string category, string action, string name, string value)
+        public async Task TrackEvent_Test(string category, string action, string name, string value)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
@@ -91,7 +91,7 @@ public void DoTrackEvent_Test(string category, string action, string name, strin
                 {"e_a", action},
             };
             //Act
-            var actual = _sut.DoTrackEvent(category, action, name, value);
+            var actual = await _sut.TrackEventAsync(category, action, name, value);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -112,7 +112,7 @@ public void DoTrackEvent_Test(string category, string action, string name, strin
         [TestCase("myCn", "mycp", "myct")]
         [TestCase("myCn", null, "myct")]
         [TestCase("myCn", "mycp", null)]
-        public void DoTrackContentImpression_Test(string contentName, string contentPiece, string contentTarget)
+        public async Task TrackContentImpression_Test(string contentName, string contentPiece, string contentTarget)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
@@ -123,7 +123,7 @@ public void DoTrackContentImpression_Test(string contentName, string contentPiec
                 { "c_n", contentName },
             };
             //Act
-            var actual = _sut.DoTrackContentImpression(contentName, contentPiece, contentTarget);
+            var actual = await _sut.TrackContentImpressionAsync(contentName, contentPiece, contentTarget);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -144,7 +144,7 @@ public void DoTrackContentImpression_Test(string contentName, string contentPiec
         [TestCase("myInteraction", "myCn", "mycp", "myct")]
         [TestCase("myInteraction", "myCn", null, "myct")]
         [TestCase("myInteraction", "myCn", "mycp", null)]
-        public void DoTrackContentInteraction_Test(string interaction, string contentName, string contentPiece, string contentTarget)
+        public async Task TrackContentInteraction_Test(string interaction, string contentName, string contentPiece, string contentTarget)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
@@ -156,7 +156,7 @@ public void DoTrackContentInteraction_Test(string interaction, string contentNam
                     { "c_i", interaction },
             };
             //Act
-            var actual = _sut.DoTrackContentInteraction(interaction, contentName, contentPiece, contentTarget);
+            var actual = await _sut.TrackContentInteractionAsync(interaction, contentName, contentPiece, contentTarget);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -177,7 +177,7 @@ public void DoTrackContentInteraction_Test(string interaction, string contentNam
         [TestCase("myKey", "myCat", 0)]
         [TestCase("myKey", null, 1)]
         [TestCase("myKey", "myCat", null)]
-        public void DoTrackSiteSearch_Test(string keyword, string category, int? countResults)
+        public async Task TrackSiteSearch_Test(string keyword, string category, int? countResults)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
@@ -188,7 +188,7 @@ public void DoTrackSiteSearch_Test(string keyword, string category, int? countRe
                  { "search", keyword },
             };
             //Act
-            var actual = _sut.DoTrackSiteSearch(keyword, category, countResults);
+            var actual = await _sut.TrackSiteSearchAsync(keyword, category, countResults);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -209,7 +209,7 @@ public void DoTrackSiteSearch_Test(string keyword, string category, int? countRe
         [TestCase(1, 0.789f)]
         [TestCase(1, 0f)]
         [TestCase(120, 3655.55f)]
-        public void DoTrackGoal_Test(int idGoal, float revenue)
+        public async Task TrackGoal_Test(int idGoal, float revenue)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
@@ -220,7 +220,7 @@ public void DoTrackGoal_Test(int idGoal, float revenue)
                  { "idgoal", idGoal.ToString() },
             };
             //Act
-            var actual = _sut.DoTrackGoal(idGoal, revenue);
+            var actual = await _sut.TrackGoalAsync(idGoal, revenue);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -235,12 +235,12 @@ public void DoTrackGoal_Test(int idGoal, float revenue)
         [Test]
         [TestCase("https://myUrl.com/action?test=1&x=5", ActionType.Download)]
         [TestCase("", ActionType.Link)]
-        public void DoTrackAction_Test(string actionUrl, ActionType actionType)
+        public async Task TrackAction_Test(string actionUrl, ActionType actionType)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
             //Act
-            var actual = _sut.DoTrackAction(actionUrl, actionType);
+            var actual = await _sut.TrackActionAsync(actionUrl, actionType);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -257,12 +257,12 @@ public void DoTrackAction_Test(string actionUrl, ActionType actionType)
         [Test]
         [TestCase(1)]
         [TestCase(33465236365.4346)]
-        public void DoTrackEcommerceCartUpdate_Test(double grandTotal)
+        public async Task TrackEcommerceCartUpdate_Test(double grandTotal)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
             //Act
-            var actual = _sut.DoTrackEcommerceCartUpdate(grandTotal);
+            var actual = await _sut.TrackEcommerceCartUpdateAsync(grandTotal);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -280,7 +280,7 @@ public void DoTrackEcommerceCartUpdate_Test(double grandTotal)
         [Test]
         [TestCase("mytoken")]
         [TestCase("")]
-        public async Task DoBulkTrack_Test(string token)
+        public async Task BulkTrack_Test(string token)
         {
             //Arrange
             var retrieveRequest = CreateAllPostOkRequestBehavior();
@@ -296,11 +296,11 @@ public async Task DoBulkTrack_Test(string token)
             }
             for (int i = 0; i < numberOfRequests; i++)
             {
-                _sut.DoTrackPageView("Page" + i);
+                await _sut.TrackPageViewAsync("Page" + i);
             }
             var expectedUrls = _sut.GetStoredTrackingActions();
             Assert.That(_sut.GetStoredTrackingActions().Length, Is.EqualTo(numberOfRequests));
-            var actual = _sut.DoBulkTrack();
+            var actual = await _sut.BulkTrackAsync();
             Assert.That(_sut.GetStoredTrackingActions().Length, Is.EqualTo(0));
             //Assert
             var actualRequest = retrieveRequest();
@@ -324,12 +324,12 @@ public async Task DoBulkTrack_Test(string token)
 
         [Test]
         [TestCase("sfaf&&Ä5", 32.32, 16.1667, 432.244, 234.324, 65.553)]
-        public void DoTrackEcommerceOrder_Test(string orderId, double grandTotal, double subTotal, double tax, double shipping, double discount)
+        public async Task TrackEcommerceOrder_Test(string orderId, double grandTotal, double subTotal, double tax, double shipping, double discount)
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
             //Act
-            var actual = _sut.DoTrackEcommerceOrder(orderId, grandTotal, subTotal, tax, shipping, discount);
+            var actual = await _sut.TrackEcommerceOrderAsync(orderId, grandTotal, subTotal, tax, shipping, discount);
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
@@ -350,12 +350,12 @@ public void DoTrackEcommerceOrder_Test(string orderId, double grandTotal, double
         }
 
         [Test]
-        public void DoPing_Test()
+        public async Task Ping_Test()
         {
             //Arrange
             var retrieveRequest = CreateAllGetOkRequestBehavior();
             //Act
-            var actual = _sut.DoPing();
+            var actual = await _sut.PingAsync();
             //Assert
             var actualRequest = retrieveRequest();
             Assert.That(actual.HttpStatusCode, Is.EqualTo(HttpStatusCode.OK));
diff --git a/Piwik.Tracker.Tests/packages.config b/Piwik.Tracker.Tests/packages.config
index b3ebe61..5bf32f5 100644
--- a/Piwik.Tracker.Tests/packages.config
+++ b/Piwik.Tracker.Tests/packages.config
@@ -11,7 +11,7 @@
   <package id="Microsoft.Owin.Host.HttpListener" version="3.0.1" targetFramework="net461" />
   <package id="Microsoft.Owin.Hosting" version="3.0.1" targetFramework="net461" />
   <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net461" />
-  <package id="NUnit" version="3.6.0" targetFramework="net45" />
+  <package id="NUnit" version="3.6.0" targetFramework="net461" />
   <package id="Owin" version="1.0" targetFramework="net461" />
   <package id="SimpleHttpMock" version="1.1.5" targetFramework="net461" />
 </packages>
\ No newline at end of file
diff --git a/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj b/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj
index 146e03b..6a98217 100644
--- a/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj
+++ b/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -13,7 +13,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Piwik</RootNamespace>
     <AssemblyName>WebTrackerTest</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <UseIISExpress>false</UseIISExpress>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
@@ -24,6 +24,8 @@
     <IISExpressAnonymousAuthentication />
     <IISExpressWindowsAuthentication />
     <IISExpressUseClassicPipelineMode />
+    <TargetFrameworkProfile />
+    <UseGlobalApplicationHostFile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -33,6 +35,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -41,17 +44,17 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Microsoft.CSharp" />
     <Reference Include="System" />
     <Reference Include="System.Data" />
-    <Reference Include="System.Core" />
     <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="System.Web.Extensions" />
-    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Net.Http" />
     <Reference Include="System.Drawing" />
     <Reference Include="System.Web" />
+    <Reference Include="System.Web.Extensions" />
     <Reference Include="System.Xml" />
     <Reference Include="System.Configuration" />
     <Reference Include="System.Web.Services" />
@@ -59,6 +62,7 @@
     <Reference Include="System.Web.DynamicData" />
     <Reference Include="System.Web.Entity" />
     <Reference Include="System.Web.ApplicationServices" />
+    <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="samples\AttributionInfoServerRead.aspx" />
@@ -106,6 +110,7 @@
     <Compile Include="samples\JavascriptGoalTracking.aspx.designer.cs">
       <DependentUpon>JavascriptGoalTracking.aspx</DependentUpon>
     </Compile>
+    <Compile Include="samples\Singleton.cs" />
     <Compile Include="samples\VisitorIdServerRead.aspx.cs">
       <DependentUpon>VisitorIdServerRead.aspx</DependentUpon>
       <SubType>ASPXCodeBehind</SubType>
diff --git a/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj.user b/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj.user
index b8e4aa5..ebd95e3 100644
--- a/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj.user
+++ b/Piwik.Tracker.Web.Samples/Piwik.Tracker.Web.Samples.csproj.user
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <UseIISExpress>false</UseIISExpress>
+  </PropertyGroup>
   <ProjectExtensions>
     <VisualStudio>
       <FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}">
diff --git a/Piwik.Tracker.Web.Samples/Web.config b/Piwik.Tracker.Web.Samples/Web.config
index 529f13a..226c874 100644
--- a/Piwik.Tracker.Web.Samples/Web.config
+++ b/Piwik.Tracker.Web.Samples/Web.config
@@ -1,11 +1,16 @@
 <?xml version="1.0"?>
 <configuration>
-    <system.web>
-        <compilation debug="true"/>
-    </system.web>
-
-    <appSettings>
-        <add key="PiwikURL" value="http://piwik" />
-        <add key="SiteId" value="1" />
-    </appSettings>
+  <system.web>
+    <compilation debug="true" targetFramework="4.5">
+      <assemblies>
+        <add assembly="System.Net.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
+      </assemblies>
+    </compilation>
+    <pages controlRenderingCompatibilityVersion="4.5"/>
+    <httpRuntime targetFramework="4.5" />
+  </system.web>
+  <appSettings>
+    <add key="PiwikURL" value="http://piwik" />
+    <add key="SiteId" value="1"/>
+  </appSettings>
 </configuration>
\ No newline at end of file
diff --git a/Piwik.Tracker.Web.Samples/samples/AttributionInfoServerRead.aspx b/Piwik.Tracker.Web.Samples/samples/AttributionInfoServerRead.aspx
index 6ab1def..c79a504 100644
--- a/Piwik.Tracker.Web.Samples/samples/AttributionInfoServerRead.aspx
+++ b/Piwik.Tracker.Web.Samples/samples/AttributionInfoServerRead.aspx
@@ -12,7 +12,7 @@ If a tracking request has been sent via javascript, this method will output the
 
 <%
     var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
-    var piwikTracker = new PiwikTracker(1, PiwikBaseUrl);
+    var piwikTracker = new PiwikTracker(Piwik.Tracker.Web.Samples.Singleton.HttpClient, 1, PiwikBaseUrl);
     piwikTracker.EnableCookies();
 
     var attributionInfo = piwikTracker.GetAttributionInfo();
diff --git a/Piwik.Tracker.Web.Samples/samples/ServerSideDeleteCookies.aspx b/Piwik.Tracker.Web.Samples/samples/ServerSideDeleteCookies.aspx
index 33cf1dd..9a31111 100644
--- a/Piwik.Tracker.Web.Samples/samples/ServerSideDeleteCookies.aspx
+++ b/Piwik.Tracker.Web.Samples/samples/ServerSideDeleteCookies.aspx
@@ -8,7 +8,7 @@ This page deletes all first party Piwik cookies using the Server Side Tracking A
 
 <%
     var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
-    var piwikTracker = new PiwikTracker(1, PiwikBaseUrl);
+    var piwikTracker = new PiwikTracker(Piwik.Tracker.Web.Samples.Singleton.HttpClient, 1, PiwikBaseUrl);
     piwikTracker.DeleteCookies();
 %>
 
diff --git a/Piwik.Tracker.Web.Samples/samples/ServerSideGoalTracking.aspx b/Piwik.Tracker.Web.Samples/samples/ServerSideGoalTracking.aspx
index 2b6f1fe..4b366e9 100644
--- a/Piwik.Tracker.Web.Samples/samples/ServerSideGoalTracking.aspx
+++ b/Piwik.Tracker.Web.Samples/samples/ServerSideGoalTracking.aspx
@@ -1,35 +1,43 @@
-<%@ Page Language="C#" %>
+<%@ Page Language="C#" Async="true" %>
 
+<%@ Import Namespace="System.Threading.Tasks" %>
 <%@ Import Namespace="Piwik.Tracker" %>
-<%@ Import Namespace="System.Net" %>
-<%@ Import Namespace="System.IO" %>
 
-This page tracks a goal conversion with the Server Side tracking API and displays the response.
-<br />
-<br />
+<script runat="server">
+    protected void Page_Load(object sender, EventArgs e)
+    {
+        RegisterAsyncTask(new PageAsyncTask(GoalTrackingAsync));
+    }
 
-<%
-    var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
+    private async Task GoalTrackingAsync()
+    {
+        var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
 
-    var piwikTracker = new PiwikTracker(1, PiwikBaseUrl);
-    piwikTracker.EnableCookies();
+        var piwikTracker = new PiwikTracker(Piwik.Tracker.Web.Samples.Singleton.HttpClient, 1, PiwikBaseUrl);
+        piwikTracker.EnableCookies();
 
-    var attributionInfo = new AttributionInfo();
+        var attributionInfo = new AttributionInfo();
 
-    attributionInfo.CampaignName = "CAMPAIGN NAME";
-    attributionInfo.CampaignKeyword = "CAMPAIGN KEYWORD";
-    attributionInfo.ReferrerTimestamp = new DateTime(2011, 04, 08, 23, 48, 24, DateTimeKind.Utc);
-    attributionInfo.ReferrerUrl = "http://www.example.org/test/really?q=yes";
+        attributionInfo.CampaignName = "CAMPAIGN NAME";
+        attributionInfo.CampaignKeyword = "CAMPAIGN KEYWORD";
+        attributionInfo.ReferrerTimestamp = new DateTime(2011, 04, 08, 23, 48, 24, DateTimeKind.Utc);
+        attributionInfo.ReferrerUrl = "http://www.example.org/test/really?q=yes";
 
-    piwikTracker.SetAttributionInfo(attributionInfo);
+        piwikTracker.SetAttributionInfo(attributionInfo);
 
-    piwikTracker.SetCustomVariable(1, "custom-variable1", "custom-variable1-value");
+        piwikTracker.SetCustomVariable(1, "custom-variable1", "custom-variable1-value");
 
-    var response = piwikTracker.DoTrackGoal(1, 42.69F);
+        statusCode.Text = (await piwikTracker.TrackGoalAsync(1, 42.69F)).HttpStatusCode.ToString();
+    }
+</script>
 
-    this.Response.Write(response.HttpStatusCode);
-%>
 
-<br />
+<form id="form1" runat="server">
+    This page tracks a goal conversion with the Server Side tracking API and displays the response.
+    <br />
+    <br />
+    <asp:literal id="statusCode" runat="server" enableviewstate="False" />
+    <br />
 
-<a href="../Default.aspx">Back</a>
\ No newline at end of file
+    <a href="../Default.aspx">Back</a>
+</form>
diff --git a/Piwik.Tracker.Web.Samples/samples/Singleton.cs b/Piwik.Tracker.Web.Samples/samples/Singleton.cs
new file mode 100644
index 0000000..3950902
--- /dev/null
+++ b/Piwik.Tracker.Web.Samples/samples/Singleton.cs
@@ -0,0 +1,9 @@
+namespace Piwik.Tracker.Web.Samples
+{
+    using System.Net.Http;
+
+    public class Singleton
+    {
+        public static readonly HttpClient HttpClient = new HttpClient();
+    }
+}
\ No newline at end of file
diff --git a/Piwik.Tracker.Web.Samples/samples/VisitScopedCustomVariableServerRead.aspx b/Piwik.Tracker.Web.Samples/samples/VisitScopedCustomVariableServerRead.aspx
index b84e2bc..9309e8c 100644
--- a/Piwik.Tracker.Web.Samples/samples/VisitScopedCustomVariableServerRead.aspx
+++ b/Piwik.Tracker.Web.Samples/samples/VisitScopedCustomVariableServerRead.aspx
@@ -8,7 +8,7 @@ This page displays visit scoped custom variables (index 1 & 2) using the Server
 
 <%
     var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
-    var piwikTracker = new PiwikTracker(1, PiwikBaseUrl);
+    var piwikTracker = new PiwikTracker(Piwik.Tracker.Web.Samples.Singleton.HttpClient, 1, PiwikBaseUrl);
     piwikTracker.EnableCookies();
 
     var customVar1 = piwikTracker.GetCustomVariable(1);
diff --git a/Piwik.Tracker.Web.Samples/samples/VisitorIdServerRead.aspx b/Piwik.Tracker.Web.Samples/samples/VisitorIdServerRead.aspx
index e060381..0f554f0 100644
--- a/Piwik.Tracker.Web.Samples/samples/VisitorIdServerRead.aspx
+++ b/Piwik.Tracker.Web.Samples/samples/VisitorIdServerRead.aspx
@@ -18,7 +18,7 @@ It is also possible to override the id using "piwikTracker.setVisitorId()"<br />
 
 <%
     var PiwikBaseUrl = ConfigurationSettings.AppSettings["PiwikURL"];
-    var piwikTracker = new PiwikTracker(1, PiwikBaseUrl);
+    var piwikTracker = new PiwikTracker(Piwik.Tracker.Web.Samples.Singleton.HttpClient, 1, PiwikBaseUrl);
     piwikTracker.EnableCookies();
 
     this.Response.Write(piwikTracker.GetVisitorId());
diff --git a/Piwik.Tracker/Piwik.Tracker.csproj b/Piwik.Tracker/Piwik.Tracker.csproj
index 062c0d9..a7286df 100644
--- a/Piwik.Tracker/Piwik.Tracker.csproj
+++ b/Piwik.Tracker/Piwik.Tracker.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -10,8 +10,9 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Piwik.Tracker</RootNamespace>
     <AssemblyName>Piwik.Tracker</AssemblyName>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -22,6 +23,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Debug\Piwik.Tracker.xml</DocumentationFile>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -31,10 +33,12 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <DocumentationFile>bin\Release\Piwik.Tracker.XML</DocumentationFile>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Net.Http" />
     <Reference Include="System.Web" />
     <Reference Include="System.Web.Extensions" />
     <Reference Include="System.Xml.Linq" />
@@ -55,11 +59,11 @@
     <Compile Include="TrackingResponse.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
   -->
 </Project>
\ No newline at end of file
diff --git a/Piwik.Tracker/PiwikTracker.cs b/Piwik.Tracker/PiwikTracker.cs
index 7c0e41d..d37f20c 100644
--- a/Piwik.Tracker/PiwikTracker.cs
+++ b/Piwik.Tracker/PiwikTracker.cs
@@ -11,15 +11,16 @@
 
 namespace Piwik.Tracker
 {
-    using System.IO;
     using System;
     using System.Collections.Generic;
-    using System.Linq;
-    using System.Net;
     using System.Globalization;
+    using System.Linq;
+    using System.Net.Http;
+    using System.Net.Http.Headers;
+    using System.Text.RegularExpressions;
+    using System.Threading.Tasks;
     using System.Web;
     using System.Web.Script.Serialization;
-    using System.Text.RegularExpressions;
 
     /// <summary>
     /// PiwikTracker implements the Piwik Tracking Web API.
@@ -141,6 +142,10 @@ public class PiwikTracker
         // Life of the session cookie (in sec)
         private const int ConfigReferralCookieTimeout = 15768000; // 6 months
 
+        // Singleton HttpClient when caller doesn't provide one
+        private static readonly Lazy<HttpClient> HttpClient = new Lazy<HttpClient>();
+
+        private readonly HttpClient _httpClient;
         private string _debugAppendUrl;
         private string _userAgent;
         private DateTimeOffset _localTime = DateTimeOffset.MinValue;
@@ -196,13 +201,40 @@ public class PiwikTracker
         /// </summary>
         /// <param name="idSite">Id site to be tracked</param>
         /// <param name="apiUrl">"http://example.org/piwik/" or "http://piwik.example.org/". If set, will overwrite PiwikTracker.URL</param>
+        /// <remarks>
+        /// This constructor initalizes an HttpClient with the default settings.
+        /// If you are using HttpClient in your application, or need to configure RequestTimeout, Proxy etc,
+        /// use the constructor that accepts HttpClient as a parameter and pass in your configured HttpClient.
+        /// </remarks>
         /// <exception cref="ArgumentException">apiUrl must not be null or empty</exception>
         public PiwikTracker(int idSite, string apiUrl)
+            : this(HttpClient.Value, idSite, apiUrl)
+        {
+        }
+
+        /// <summary>
+        /// Builds a PiwikTracker object, used to track visits, pages and Goal conversions
+        /// for a specific website, by using the Piwik Tracking API.
+        /// If the tracker is used within a web page or web controller, the following information are pre-initialised :
+        /// URL Referrer, current page URL, remote IP, Accept-Language HTTP header and User-Agent HTTP header.
+        /// </summary>
+        /// <param name="httpClient">A singleton HttpClient that is used throughout your application. See <see href="https://msdn.microsoft.com/en-us/library/system.net.http.httpclient(v=vs.110).aspx#Anchor_5">HttpClient class remarks</see></param>
+        /// <param name="idSite">Id site to be tracked</param>
+        /// <param name="apiUrl">"http://example.org/piwik/" or "http://piwik.example.org/". If set, will overwrite PiwikTracker.URL</param>
+        /// <exception cref="ArgumentException">apiUrl must not be null or empty</exception>
+        public PiwikTracker(HttpClient httpClient, int idSite, string apiUrl)
         {
             if (string.IsNullOrEmpty(apiUrl))
             {
-                throw new ArgumentException("Piwik api url must not be emty or null.", nameof(apiUrl));
+                throw new ArgumentException("Piwik api url must not be empty or null.", nameof(apiUrl));
             }
+
+            if (httpClient == null)
+            {
+                throw new ArgumentNullException(nameof(httpClient), $"Initialize a single instance of HttpClient in your application and pass that instance to the {nameof(httpClient)} parameter.");
+            }
+
+            _httpClient = httpClient;
             PiwikBaseUrl = FixPiwikBaseUrl(apiUrl);
             IdSite = idSite;
 
@@ -229,17 +261,6 @@ public PiwikTracker(int idSite, string apiUrl)
         /// </summary>
         public int IdSite { get; }
 
-        /// <summary>
-        /// Gets or sets the maximum number of seconds the tracker will spend waiting for a response
-        /// from Piwik. Defaults to 600 seconds.
-        /// </summary>
-        public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(600);
-
-        /// <summary>
-        /// Gets or sets the proxy used for web-requests, or <c>null</c> if no proxy is used.
-        /// </summary>
-        public IWebProxy Proxy { get; set; }
-
         /// <summary>
         /// By default, Piwik expects utf-8 encoded values, for example
         /// for the page URL parameter values, Page Title, etc.
@@ -395,7 +416,7 @@ public string GetCustomTrackingParameter(string trackingApiParameter)
         }
 
         /// <summary>
-        /// Gets the stored tracking actions, that have been stored for bulkRequest <see cref="EnableBulkTracking"/>, <see cref="DoBulkTrack"/>.
+        /// Gets the stored tracking actions, that have been stored for bulkRequest <see cref="EnableBulkTracking"/>, <see cref="BulkTrackAsync"/>.
         /// </summary>
         /// <returns></returns>
         public string[] GetStoredTrackingActions()
@@ -585,10 +606,10 @@ protected string GetCookieName(string cookieName)
         /// </summary>
         /// <param name="documentTitle">Page title as it will appear in the Actions > Page titles report</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackPageView(string documentTitle = null)
+        public Task<TrackingResponse> TrackPageViewAsync(string documentTitle = null)
         {
             string url = GetUrlTrackPageView(documentTitle);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -599,10 +620,10 @@ public TrackingResponse DoTrackPageView(string documentTitle = null)
         /// <param name="name">(optional) The Event's object Name (a particular Movie name, or Song name, or File name...)</param>
         /// <param name="value">(optional) The Event's value</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackEvent(string category, string action, string name = "", string value = "")
+        public Task<TrackingResponse> TrackEventAsync(string category, string action, string name = "", string value = "")
         {
             var url = GetUrlTrackEvent(category, action, name, value);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -612,10 +633,10 @@ public TrackingResponse DoTrackEvent(string category, string action, string name
         /// <param name="contentPiece">The actual content. For instance the path to an image, video, audio, any text</param>
         /// <param name="contentTarget">(optional) The target of the content. For instance the URL of a landing page.</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackContentImpression(string contentName, string contentPiece = "Unknown", string contentTarget = null)
+        public Task<TrackingResponse> TrackContentImpressionAsync(string contentName, string contentPiece = "Unknown", string contentTarget = null)
         {
             var url = GetUrlTrackContentImpression(contentName, contentPiece, contentTarget);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -627,10 +648,10 @@ public TrackingResponse DoTrackContentImpression(string contentName, string cont
         /// <param name="contentPiece">The actual content. For instance the path to an image, video, audio, any text</param>
         /// <param name="contentTarget">(optional) The target the content leading to when an interaction occurs. For instance the URL of a landing page.</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackContentInteraction(string interaction, string contentName, string contentPiece = "Unknown", string contentTarget = null)
+        public Task<TrackingResponse> TrackContentInteractionAsync(string interaction, string contentName, string contentPiece = "Unknown", string contentTarget = null)
         {
             var url = GetUrlTrackContentInteraction(interaction, contentName, contentPiece, contentTarget);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -641,10 +662,10 @@ public TrackingResponse DoTrackContentInteraction(string interaction, string con
         /// <param name="category">(optional) Search engine category if applicable</param>
         /// <param name="countResults">(optional) results displayed on the search result page. Used to track "zero result" keywords.</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackSiteSearch(string keyword, string category = "", int? countResults = null)
+        public Task<TrackingResponse> TrackSiteSearchAsync(string keyword, string category = "", int? countResults = null)
         {
             var url = GetUrlTrackSiteSearch(keyword, category, countResults);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -653,10 +674,10 @@ public TrackingResponse DoTrackSiteSearch(string keyword, string category = "",
         /// <param name="idGoal">Id Goal to record a conversion</param>
         /// <param name="revenue">Revenue for this conversion</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackGoal(int idGoal, float revenue = 0)
+        public Task<TrackingResponse> TrackGoalAsync(int idGoal, float revenue = 0)
         {
             string url = GetUrlTrackGoal(idGoal, revenue);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -665,11 +686,11 @@ public TrackingResponse DoTrackGoal(int idGoal, float revenue = 0)
         /// <param name="actionUrl">URL of the download or outlink</param>
         /// <param name="actionType">Type of the action: 'download' or 'link'</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackAction(string actionUrl, ActionType actionType)
+        public Task<TrackingResponse> TrackActionAsync(string actionUrl, ActionType actionType)
         {
             // Referrer could be udpated to be the current URL temporarily (to mimic JS behavior)
             string url = GetUrlTrackAction(actionUrl, actionType);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -707,10 +728,10 @@ public void AddEcommerceItem(string sku, string name = "", List<string> categori
         /// </summary>
         /// <param name="grandTotal">Cart grandTotal (typically the sum of all items' prices)</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackEcommerceCartUpdate(double grandTotal)
+        public Task<TrackingResponse> TrackEcommerceCartUpdateAsync(double grandTotal)
         {
             string url = GetUrlTrackEcommerceCartUpdate(grandTotal);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -721,11 +742,11 @@ public TrackingResponse DoTrackEcommerceCartUpdate(double grandTotal)
         /// Response
         /// </returns>
         /// <exception cref="System.InvalidOperationException">Error: you must call the function DoTrackPageView or DoTrackGoal from this class, before calling this method DoBulkTrack()</exception>
-        public TrackingResponse DoBulkTrack()
+        public async Task<TrackingResponse> BulkTrackAsync()
         {
             if (!_storedTrackingActions.Any())
             {
-                throw new InvalidOperationException("Error: you must call the function DoTrackPageView or DoTrackGoal from this class, before calling this method DoBulkTrack()");
+                throw new InvalidOperationException($"Error: you must call the function {nameof(TrackPageViewAsync)} or {nameof(TrackGoalAsync)} from this class, before calling this method DoBulkTrack()");
             }
 
             var data = new Dictionary<string, object>();
@@ -738,7 +759,7 @@ public TrackingResponse DoBulkTrack()
             }
 
             var postData = new JavaScriptSerializer().Serialize(data);
-            var response = SendRequest(PiwikBaseUrl, "POST", postData, true);
+            var response = await SendRequestAsync(PiwikBaseUrl, "POST", postData, true).ConfigureAwait(false);
 
             _storedTrackingActions = new List<string>();
 
@@ -759,10 +780,10 @@ public TrackingResponse DoBulkTrack()
         /// <param name="shipping">Shipping amount for this order</param>
         /// <param name="discount">Discounted amount in this order</param>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoTrackEcommerceOrder(string orderId, double grandTotal, double subTotal = 0, double tax = 0, double shipping = 0, double discount = 0)
+        public Task<TrackingResponse> TrackEcommerceOrderAsync(string orderId, double grandTotal, double subTotal = 0, double tax = 0, double shipping = 0, double discount = 0)
         {
             string url = GetUrlTrackEcommerceOrder(orderId, grandTotal, subTotal, tax, shipping, discount);
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -773,11 +794,11 @@ public TrackingResponse DoTrackEcommerceOrder(string orderId, double grandTotal,
         /// ping requests will create a new visit using the last action in the last known visit.
         /// </summary>
         /// <returns>HTTP Response from the server or null if using bulk requests.</returns>
-        public TrackingResponse DoPing()
+        public Task<TrackingResponse> PingAsync()
         {
             var url = GetRequest(IdSite);
             url += "&ping=1";
-            return SendRequest(url);
+            return SendRequestAsync(url);
         }
 
         /// <summary>
@@ -915,7 +936,7 @@ protected internal string GetUrlTrackEcommerce(double grandTotal, double subTota
         /// <summary>
         /// Builds URL to track a page view.
         /// </summary>
-        /// <see cref="DoTrackPageView"/>
+        /// <see cref="TrackPageViewAsync"/>
         /// <param name="documentTitle">Page view name as it will appear in Piwik reports</param>
         /// <returns>URL to piwik.php with all parameters set to track the pageview</returns>
         public string GetUrlTrackPageView(string documentTitle = "")
@@ -945,7 +966,7 @@ public string GetUrlTrackPageView(string documentTitle = "")
         /// or
         /// You must specify an Event action (click, view, add...). - action
         /// </exception>
-        /// <see cref="DoTrackEvent" />
+        /// <see cref="TrackEventAsync" />
         public string GetUrlTrackEvent(string category, string action, string name = "", string value = "")
         {
             if (string.IsNullOrWhiteSpace(category))
@@ -982,7 +1003,7 @@ public string GetUrlTrackEvent(string category, string action, string name = "",
         /// URL to piwik.php with all parameters set to track the pageview
         /// </returns>
         /// <exception cref="ArgumentException">You must specify a content name - contentName</exception>
-        /// <see cref="DoTrackContentImpression" />
+        /// <see cref="TrackContentImpressionAsync" />
         public string GetUrlTrackContentImpression(string contentName, string contentPiece, string contentTarget)
         {
             if (string.IsNullOrWhiteSpace(contentName))
@@ -1020,7 +1041,7 @@ public string GetUrlTrackContentImpression(string contentName, string contentPie
         /// or
         /// You must specify a content name - contentName
         /// </exception>
-        /// <see cref="DoTrackContentImpression" />
+        /// <see cref="TrackContentImpressionAsync" />
         public string GetUrlTrackContentInteraction(string interaction, string contentName, string contentPiece, string contentTarget)
         {
             if (string.IsNullOrWhiteSpace(interaction))
@@ -1056,7 +1077,7 @@ public string GetUrlTrackContentInteraction(string interaction, string contentNa
         /// <param name="category">The category.</param>
         /// <param name="countResults">The count results.</param>
         /// <returns></returns>
-        /// <see cref="DoTrackSiteSearch" />
+        /// <see cref="TrackSiteSearchAsync" />
         public string GetUrlTrackSiteSearch(string keyword, string category, int? countResults)
         {
             var url = GetRequest(IdSite);
@@ -1075,7 +1096,7 @@ public string GetUrlTrackSiteSearch(string keyword, string category, int? countR
         /// <summary>
         /// Builds URL to track a goal with idGoal and revenue.
         /// </summary>
-        /// <see cref="DoTrackGoal"/>
+        /// <see cref="TrackGoalAsync"/>
         /// <param name="idGoal">Id Goal to record a conversion</param>
         /// <param name="revenue">Revenue for this conversion</param>
         /// <returns>URL to piwik.php with all parameters set to track the goal conversion</returns>
@@ -1093,7 +1114,7 @@ public string GetUrlTrackGoal(int idGoal, float revenue = 0)
         /// <summary>
         /// Builds URL to track a new action.
         /// </summary>
-        /// <see cref="DoTrackAction"/>
+        /// <see cref="TrackActionAsync"/>
         /// <param name="actionUrl">URL of the download or outlink</param>
         /// <param name="actionType">Type of the action: 'download' or 'link'</param>
         /// <returns>URL to piwik.php with all parameters set to track an action</returns>
@@ -1421,7 +1442,7 @@ public void DisableCookieSupport()
             _configCookiesDisabled = true;
         }
 
-        private TrackingResponse SendRequest(string url, string method = "GET", string data = null, bool force = false)
+        private async Task<TrackingResponse> SendRequestAsync(string url, string method = "GET", string data = null, bool force = false)
         {
             // if doing a bulk request, store the url
             if (_doBulkRequests && !force)
@@ -1440,27 +1461,30 @@ private TrackingResponse SendRequest(string url, string method = "GET", string d
                 return null;
             }
 
-            var request = (HttpWebRequest)WebRequest.Create(url);
-            request.Method = method;
-            request.UserAgent = _userAgent;
-            request.Headers.Add("Accept-Language", _acceptLanguage);
-            request.Timeout = (int)RequestTimeout.TotalMilliseconds;
-            if (Proxy != null)
+            var request = new HttpRequestMessage
             {
-                request.Proxy = Proxy;
+                RequestUri = new Uri(url, UriKind.Absolute),
+                Method = new HttpMethod(method)
+            };
+            if (!string.IsNullOrEmpty(_userAgent))
+            {
+                request.Headers.TryAddWithoutValidation("User-Agent", _userAgent);
+            }
+
+            if (!string.IsNullOrEmpty(_acceptLanguage))
+            {
+                request.Headers.AcceptLanguage.Add(new StringWithQualityHeaderValue(_acceptLanguage));
             }
 
             if (!string.IsNullOrEmpty(data))
             {
-                request.ContentType = "application/json";
-                using (var streamWriter = new StreamWriter(request.GetRequestStream()))
-                {
-                    streamWriter.Write(data);
-                }
+                request.Content = new StringContent(data);
+                request.Content.Headers.ContentType.MediaType = "application/json";
             }
-            using (var result = (HttpWebResponse)request.GetResponse())
+
+            using (var response = await _httpClient.SendAsync(request).ConfigureAwait(false))
             {
-                return new TrackingResponse { HttpStatusCode = result.StatusCode, RequestedUrl = url };
+                return new TrackingResponse { HttpStatusCode = response.StatusCode, RequestedUrl = url };
             }
         }
 
@@ -1724,7 +1748,9 @@ protected Dictionary<string, string[]> GetCustomVariablesFromCookie()
             {
                 return new Dictionary<string, string[]>();
             }
-            return new JavaScriptSerializer().Deserialize<Dictionary<string, string[]>>(HttpUtility.UrlDecode(cookie.Value ?? string.Empty));
+
+            return new JavaScriptSerializer().Deserialize<Dictionary<string, string[]>>(HttpUtility.UrlDecode(cookie.Value ?? string.Empty)) ??
+                         new Dictionary<string, string[]>();
         }
 
         private string FormatDateValue(DateTimeOffset date)