All the funds gathered with donations go exclusively for covering server costs, upgrading speed, adding new services and features.
Remember that the word "donation" describes an act of giving money without expecting anything in return, however in appreciation and promotion of donating for the server, you also get a reward for the kind gesture.

 

For more info scroll down to the bottom of the page. If you have more questions about donation rewards, ask in the forum or email us and we will explain how these things work.