Donating Rewards

Alright silly question, but just trying to grab some idea's. Alright so how can I reward those that have donated to a forum? Can some members give me some idea's, because I'm just as clueless right now lol

I got a slight feeling that this not kinda a support question anyway,

-You can make them a group(example :donators group, VIP member's group etc.) and give them a color on the online list
-you can also give them rank(example: donator, VIP member etc.)
-You can give them a special forum where staff and the donator can only see it

That's all I can think of as off now, This way you can show them their importance to the forum