By donating to the Servers, you are helping keep the servers online and contributing towards the monthly bill.
You are also showing your appreciation for the server :)
Donations are handled by PayPal securely, all details you enter are encrypted. This is a very secure procedure, in which I (Steveh) do not see your card details at any time.
All donations go directly to the server, and if a user donates, they will recieve a Donator Rank throughout the gameservers after contacting Steveh with the email address that you donated with.
Thank you, and have a nice day :)