The New York Times writes:
The new DoubleClick advertising exchange will bring Web publishers and advertising buyers together on a Web site where they can participate in auctions for ad space.
David Rosenblatt, the company�s chief executive described the exchange as a mix of eBay and Sabre, the airline reservations system that travel agents use. The service will let advertisers see information about what competitors bid for particular ads, in the same way that eBay shows visitors past bids. And it will let publishers try to ensure that they sell their ad spots at the highest possible price, the way that airlines try to do with the seats they sell.