Today, Google announced that it is opening the new DoubleClick Ad Exchange, a real-time marketplace for display advertising space.

By establishing an open marketplace where prices are set in a real-time auction, the Ad Exchange enables display ad space to be allocated much more efficiently and easily across the web.

“Better technology can help make display advertising work better for all involved,” said Neal Mohan, Vice President of Product Management at Google. “We’re focused on growing the display advertising pie for everyone. The DoubleClick Ad Exchange is a major part of that goal.”

The new DoubleClick Ad Exchange has been rebuilt using Google’s technology and infrastructure. It contains a wide variety of key features that will help improve returns for advertisers and enable publishers to get the most value out of their online content.

On the “sell side”, participation in the new Ad Exchange is designed for major online publishers. It already includes a wide variety of large premium publishers including newspapers, large portals, entertainment and branded sites. In addition, ad space on Google’s third party AdSense publisher sites, representing over 76% of U.S. online audiences and 73% of global online audiences1, is being made available through the new Ad Exchange. This will increase the volume of quality display advertisers available to Google’s AdSense publishers.

On the “buy side”, the new Ad Exchange is designed for ad networks and agency networks - companies that connect web sites with advertisers. It already includes over 40 ad networks across North America and Europe, including most of the 25 largest ad networks in the US2, with more now to be added. Additionally, AdWords advertisers will be able to run ads on sites in the Ad Exchange, using their existing AdWords interface.

Features of the new Ad Exchange include a completely new interface; a “real-time bidding” feature to allow ad networks to use their own technology to bid on an impression-by-impression basis; a “dynamic allocation” system, which automatically generates online publishers the highest return for every impression by allocating ads to the highest-paying sales channel, based on real time data; more granular publisher and advertiser controls; payments and clearing managed by Google; and a new API to allow ad networks to extend the functionality of the Ad Exchange.