Google has begun testing expandable ads, ads that expand in size when clicked on, on the Google content network. The ads will be limited to expanding to double the original size and can “include a streaming video or other content designed to engage users through an interactive experience.” In addition to limiting the size of expanded ads, ads will expand only after a user clicks on the ad, ads will be required to be able to be closed by the user at any time, and ads must comply with Google’s standard AdWords image ad policies. The ads are price on a cost-per-click (CPC) or cost-per-impression (CPM) basis, CPC ads will only accrue clicks when a user visits the advertisers landing page and not when a user clicks to expand the ad. According to a post on the Inside AdWords blog the test is currently limited to the U.S. advertiser who advertise through Google’s 3rd Party Ad Serving program and the test will be expanded, but no details were given.