Thanks for your interest in advertising on Retro Reviews. Advertising is handled via Project Wonderful, and sold off by the day to the highest bidder. If there are no paying bidders, or if there are slots proclaiming "Your Ad Here," advertising is free until someone puts in a bid.
It's not unusual for advertisers to end up paying only a penny or two per day for advertising on Retro Reviews, getting a cost per click of a tiny slice of a penny.
Retro Reviews readers are tech-savvy gamers, roughly 70% FireFox users, and of course, interested in old or retro-style gaming.
You can find more information on the bidding system at the Project Wonderful website. If you'd like to go directly to the bidding pages for Retro Reviews, here are the links:
160*600 Skyscraper Ad
125*125 Button Ads
Thanks!
Retro Reviews
http://www.retroreviews.net/staticpages/index.php/advertising