A sign is displayed outside of the Google headquarters in 2008 in Mountain View, California. Google announced the launch of the DoubleClick Ad Exchange, billed as a "real-time marketplace" where it will help large online publishers and ad networks and agency networks buy and sell display advertising space.

Google, which dominates text-based Web advertising, launched a push into the display ad market on Friday in a direct challenge to rival Yahoo!

Google, in a blog post, announced the launch of the DoubleClick Ad Exchange, billed as a "real-time marketplace" where it will help large online publishers and ad networks and agency networks buy and sell display advertising space.

Google has become a Web powerhouse through search advertising -- selling relevant text ads on websites and alongside search results -- while Yahoo! has focused more on display ads, which include videos, images and interactivity.

A major push by Google into the display ad market had been expected since its purchase last year of display ad company DoubleClick for 3.1 billion dollars.

Neal Mohan, a Google vice president for product management, said prices will be set in the Ad Exchange marketplace in a real-time auction allowing "display ads and ad space to be allocated much more efficiently."

Currrently, "some publishers are left with up to 80 percent of their ad space unsold," he said. "It?s like airlines flying with their planes mostly empty."

Mohan said Ad Exchange would simplify the system for buying and selling display ads and provide advertisers with better measurement techniques.

"We believe that a better system built on better technology can help grow the display advertising pie and benefit everyone," he said.

"With a multitude of display ad formats, and thousands of websites, it often takes thousands of hours for advertisers to plan and manage their display ad campaigns," Mohan said. "With this complexity, lots of advertisers today just don't bother, or don't invest as much as they would like."

DoubleClick will "help advertisers and publishers manage campaigns and ad formats across thousands of websites and from thousands of advertisers," he said. "This improves returns for advertisers and enables publishers to get the most value out of their online content."

Mohan also said the Ad Exchange can be used by advertisers and publishers who currently use Google's AdWords and AdSense services.

© 2009 AFP