haven't heard about ebay adcontext. ebay is developing an advertising system called adcontext that is being touted as a possible competitor to google adense program Like AdSense, adContext will analyze page content in order to serve contextually-sensitive ads. unlike adsense adcontext ads link back to ebay not to random sites
Speculation abounds that eBay will eventually expand the program to be a full-fledged AdSense competitor