I run a forum for a club (car) and we make enough from the forum to host it on a dedicated server and have money left over for club events throughtout the year.
Members pay for certain features on the site...and they feel they are helping the club by doing so...I feel if I was running it for myself the profit would be no where near as good.
Plus we have a strict rule on business's advertising on our forum and as such charge them too...we make a nice amount from that...but it all goes back to the club...so really the members are the winners!!
So far I get a small revenue from my sites. But they are indeed in their infancy and they are growing steadily. So far I made 200 USD from Adsense, but I'm starting enjoying admining so much that I overlook this aspect. Anyway, little by little I should be able to earn some more.