Google expands its AdSense with expandable ads

Google is expanding its AdSense programme - literally. The Web search giant announced Wednesday in a blog post that it is pitching advertisers on the use of expandable ad units, those adverts that start out as banners or square ads and launch larger ads that cover much of the Web site's content.

For the time being, the expanding ad option is only available to US advertisers already participating in Google's third party ad serving programme, a group that numbers in the hundreds. Those brands are placing ads on handpicked sites in the AdSense network using Google's placement targeting option, the company said.

Expanding ads can be produced by either DoubleClick Rich Media or Eyeblaster. To prevent accidental expansions that aggravate consumers and web site owners, Google does not allow ad expansions to be triggered by roll-overs.

Many users may find expandable ads annoying, but as Google points out, the format could be valuable to both advertisers and customers when used to show movie trailers, video game clips, or other images that require greater emphasis on detail.

As with other image ad offerings from Google, the units can be purchased on either a cost-per-click or cost-per-thousand basis. Expanding ads are available immediately on any AdSense-ready sites that already accept image ads. Those properties are not permitted to opt out of expanding ads without turning off all image ads.

Rival ad sellers like Platform-A, Microsoft, and Yahoo have long offered expanding ads. Google has been slower than its competitors to offer rich ad formats, partly owing to its legacy of text-based ad listings and partly to its emphasis on providing a clean user experience.

It first began testing traditional banners in 2004, and since then has gradually rolled out other visually elaborate ad options, including its multi-function Gadget Ads, video ads, and hybrid units that combine content and advertising within publisher ad space.