Just curious, the owners of it says they barely make any money out of it. Also, does it matter if the same people go on it over and over again? If for some reason you need the url address to that site, its sphaxball.com ~milos
$10 USD? you serious? that's nothing.. i heard forums could make biiiiig money with ad sense and certain amout of views
As far as I know, forums don't a lot on adsense (relative per visitor). Maybe if you have a niche forum with highly relevant sponsored/branded ads...
500 active users per month? not really relevant... active users are probably not going to click on ads... much less google ads. how many sites visitors in comparison to registrations, active members, etc. would be a better scenario to analyze...
Forums can make a LOT. I can't really give you much of an estimate because there are several ways to monetize a forum. There's ads, user upgrades, and word replacing. You could replace certain words for example adf.ly with your referral link. I know mybb has the capabilities of replacing certain words/phrases. Anyways forums can make good money, but they're VERY VERY hard to start nowadays. If you really want to start a forum and get big, you'll need to work at least 5 hours per day on your forum doing SEO, building content, and recruiting members. Overall forums are very hard to start. Ounce you hit about 50,000 members your forum should operate itself by then.