Although Google executives revealed the beta during a marketing summit for the auto industry, the Gadget Ads will be available to all ad categories by this summer's planned launch.

Bloggers around the Web, dubbing them "Google Gadgets," have written about these ad units, a version of which are available for use with the new personalized iGoogle interface.

Like widgets, the HTML-based applications offer advertisers the option to add flash, video, real-time feed, and transaction functionality to typically static display ads.

"But they don't have to be complex," said Zal Bilimoria, product marketing manager, Google. "Anyone who can build a Web site can have a Gadget Ad."

Advertisers will incur no serving or hosting costs to run Gadget Ads, which come in standard IAB ad formats. The ads will be placed through the existing auction system, allowing marketers the option of bidding by publisher's site or content theme. With either CPC or CPM pricing, Gadget Ads can be integrated into an existing AdSense budget.

As rich media technology becomes more readily available, advertisers are increasingly turning to widget-like applications for solutions that don't require users to actively search for content or click through to a landing page.

To support these changes, Google has developed specific "interaction reporting" tools as part of its Google Analytics performance feedback services.

Marketers using Gadget Ads will be able to determine which features users are clicking on the most--whether a 'how-to video,' a 'savings calculator,' or a live feed--and then edit them accordingly. As "user engagement" evolves into a key accountability metric for measuring digital ad strategies, it will also become increasingly important for advertisers to track these statistics.

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