https://ebay.admarketplace.net/ebay/servlet/ebay

A few points of interest. For starters, the max bidder doesn't necessarily get a "top position" like traditional PPC engines, but rather more frequently served banner ad impressions. Also, the max bid amount is like Overture, in that your max might be $2.00, and your next closest competitor's max is $1.50. Therefore, you will automatically pay $1.51... Perhaps the most humorous provision of this new program is that advertisers can't bid on keywords that direct visitors to "unfounded criticism" of particular brand names. So, I wonder who determines whether criticism is unfounded. Ah well, so much for free speech.

I wonder how much traffic Ebay has in order to justify building a PPC system like this. It got me thinking. I wonder if a similar system for use in other high traffic, commerce oriented websites. (ie., Amazon) would work?