Expandable!

Google is testing expandable ads for its AdSense and AdWords programs.

When a user clicks on a display ad, it will temporarily expand over the content. According to Google, ads will not not expand to more than double their original width or height, and users may close the ads at any time.

And while it takes one click to make the ad expand, publishers will not be compensated their agreed-upon cost-per-click rates until users click a second time, at which point they'll be driven to the advertiser's website.

The AdSense expandable ad program is available in North America and Europe. Languages include Dutch, English, French, German, Italian, Portuguese, or Spanish.

For AdWords, Google claims expandable ads are still in beta. These are open to US advertisers currently participating in its 3rd Party Ad Serving Program.

In early February, Google broadened its beta pool for an expandable form of pay-per-click advertising. The program, dubbed Product PlusBox, provides additional product data to users without driving them off Google's search results page.