Google is testing a new interactive ad format that builds on the concept of “widgets” that can be embedded in web pages.

Google Gadget Ads, which are being tested by a small group of Google AdWords advertisers, are being expanded to include more advertisers, according to Google.

Google said Gadget Ads will allow advertisers to interact with users and hold their attention for longer than regular ads. Advertisers will also be able to see how many users interact with the ads, as well as how they interacted with the ads, Google said.

Gadget Ads are small applications, or widgets, that combine real-time data feeds, images and video with traditional advertising content. They can be developed using Flash, HTML or both, Google said. Users can embed them into their blogs or iGoogle home pages. Gadget ads are built on an open system, so anyone can set up and run ads on the Google content network, Google said.

Google posted several examples of the Gadget ads on its website. An ad for the Six Flags theme park includes a simple game and a link to "add to your Google home page."

The Six Flags ad delivered 94.5 million impressions to 17.1 million unique users, and users interacted with the ad about 200,000 times, Google said. About 0.3 percent of those exposed to the gadget ads interact with them, Google said. In comparison, direct mail generates a response rate of 2.18 percent, according to 2006 figures from the Direct Marketing Association.

The gadget ads run on Google's AdSense advertising network and are priced by the number of clicks or number of impressions. It's unclear when this testing phase will end. However, Google said the ads will ultimately be available in 20 languages and 100 countries.

"The introduction of this new advertising format provides advertisers and agencies worldwide with an imaginative, dynamic way to interact with consumers," said Susan Wojcicki, Google's vice president of product management, in a statement.

James Niccolai of the IDG News Service contributed to this report.