Hmmm good question... The top banners go for like $2500 (maybe a bit cheaper if you play with Eric's weiner like I do LOL!). I would guesstimate there are about 30 banners in rotation... There are several 250x60 banners, I am not sure what they go for but I would guess $500-1000 per month x 20 sponsors.
The skinning of the board goes for between 25-35k (I believe), there are about 10-15 sponsors a year that take the plunge and skin the site. Then there are the floating banner ads that come up (ie. Sexsearch and Webcamcash).
So I would say it's very securely over 1 mil per year, maybe closer to 2 mil? Fucking great site and incredible money maker for Adult.com
Kudos to them for doing a great job!
DH