ODEM Airdropper

Airdropper contract for token bounty distribution.

Parts of this implementation (SafeMath and Ownable) are taken from OpenZeppelin v1.8.0, with modification to support Solidity v0.4.21.

Why an airdropper?

As part of On-Demand Education Marketplace’s bounty and rewards campaign, the company is obliged to transfer more than one million ODEM Tokens to thousands of users. Transferring them one user at a time would be both tedious and expensive.

Both of these problems can be managed by using an airdropper contract to complete many individual transfers within one combined transaction. The contract reduces the number of transactions and fees associated with the distribution.

Unique features

This airdropper differs from most others in that it never holds tokens. Instead it calls ERC20's transferFrom to transfer tokens directly from a given source address to the recipients. This has two distinct advantages:

• ODEM has already published the address which holds the tokens to be distributed as bounty. The recipients will see that their tokens came directly from this address, so they can verify that they received their rewards in good order. The address is recorded in the ODEM ICO repository.

• The contract can be tested on the main network without interfering with the allocation of bounty tokens, and without the need to deploy a new instance after testing.

This airdropper also has a method to self-destruct, which is called as soon as tokens have been distributed to all recipients. This prevents it from being used as an attack vector in any future zero-day exploits, and also takes some load off the Ethereum network — it's important to be a good neighbour.