One that's gaining traction is New York-based Right Media. Founder Mike Walrath spent three years at online ad pioneer Double-Click, from the end of the boom into the bust, and ultimately deduced that the system for buying and selling online advertising was a mess: There was plenty of space available and plenty of demand, but there was no structure to connect them. Plus, he kept hearing complaints that Google's auction system wasn't transparent enough.
So Walrath built an exchange, called RMX, that's become a kind of eBay for display-ad inventory. Bidders specify their audience and Right Media's system predicts where the ads will work best. The software matches them with sellers in a fraction of a second and serves up the ad; Right Media takes an 8 percent cut.
Business took off so fast it almost killed the company. The exchange launched in April 2005 with a few small ad networks and a handful of ad buyers. By the fall the number of impressions traded on the exchange had soared to 20 billion a month.
Full story from CNN: [money.cnn.com...]