I'm selling 125 x 125 ad slots on my blog, for a minimum bid of $0.50 per day right now. Prices go up or down depending on the advertisers bidding for the ad spot. You should be the highest bidder to get your site displayed immediately. You see all the reports, page impressions and number of clicks. If you don't like the performance, you can cancel immediately. Check my blog, http://www.macuha.com to see them in action. The ads are on the header, and there's a link there for you to place your bid. My site gets 4000+ pageviews per day. You'll see all the statistics on the bidding page for more details. The ads are powered by Project Wonderful.