Google has just launched their DoubleClick Ad Exchange which brings together all types of display ad buyers and sellers, as well as AdWords, and delivers those ads to AdSense publisher web sites.
Through the new DoubleClick Ad Exchange big-time and small-time advertisers can now buy targeted display ads on thousands of DoubleClick ad-serving websites, which could boost Google’s revenue, and hurt Yahoo in the display adverting market.
Traditionally, publishers and advertisers using Google’s AdSense and AdWords products would have to manually plan their display ad campaigns. Now, publishers can tap into Google’s ecosystem for ads where prices are set in a real-time auction and advertisers can access a large pool of inventory within one platform.

Google says the benefits for publishers include the real-time allocation, letting them allocate ad space to the advertiser that pays the most at a given time; access to more advertisers; greater control over advertisers and ad formats, a sleeker UI, and payment system managed completely by Google.
The new API also allows advertisers and advertising networks to integrate their own functionality and systems into the Ad Exchange, while giving them access to far more clients and web sites than before.
Google bought display ad provider DoubleClick in 2007 for $3.1 billion in cash, after winning a bidding war with Microsoft. This new Ad Exchange is sure to allow Google to dominate the display ad marketplace, pushing Yahoo into the number 2 spot for some time to come.