In a move designed to change the texture of mobile Web content, Google is integrating smaller display ads designed for mobile browsers, into its AdWords service starting today. But it won't fool many into thinking it's not playing catch-up.

The leader in online display image advertising right now is actually DoubleClick, which is now a Google division but is still allowed to do its own thing. In the meantime, Google's increasing emphasis on mobile device platforms -- including its own Android -- is pushing it to become a display ad leader for that segment.

This morning, Google took a step in that direction by announcing the integration of mobile image ads -- smaller pictures that don't have to be shrunken to be seen on resolutions that average only 320 x 200 -- into its AdWords program. Technically, AdWords is Google's contextual ad system, though this integration opens up display ad capabilities for click-throughs designed to link to mobile-only Web sites.

"For advertisers, mobile image ads serve as a branding tool and have shown to have good click-through rates," reads an official blog post this morning from marketing manager Alexandra Kenin. "Advertisers using mobile image ads will also benefit because we only show one image ad per mobile page. For publishers, mobile image ads provide added flexibility. They can now choose to show text ads, image ads, or a mix of both and Google will dynamically return the ad that we expect will perform best at the time the ad is shown."

In a departure from the norm for Google, this new service is being rolled out as a complete feature of AdWords rather than as a limited beta.

Google did start a beta test of pay-per-click mobile text ads in September 2006. But that test began just weeks before Yahoo launched its first beta test of mobile image ads in November, in a trial run that featured Pepsi-Cola. Since that time, Yahoo has actually pulled out front in mobile platforms; and AOL is now being seen as a major challenger, especially after its May 2007 purchase of mobile display and video ad platform provider Third Screen Media. AOL wrapped Third Screen into its Platform-A division, which is perceived as the challenger to Google and Yahoo that's ejecting Microsoft from any discussion of Web advertising leadership.

The Google blog this afternoon characterized mobile image ads as "a new way to interact with mobile content," without noting that the preferred form factors for that mobile content may have been determined by Yahoo's testing.