Consumers are moving off of the desktop and on to their mobile devices, but advertisers are not following them at the same pace. Just 5% of online advertising revenue in 2011 came from mobile, according to the Interactive Advertising Bureau .
In an effort to change this equation--and increase its own mobile ad revenue--YouTube introduced a new type of ad for its mobile website today. Called TrueView, it gives users a choice of whether to watch a video ad and only charges the advertiser when they do so.
While the ad format has been available on YouTube's standard website since 2010, YouTube's mobile advertising has until now been focused on banner ads and promoted videos. YouTube executives told the New York Times  that TrueView is particularly suited for mobile because it doesn't interrupt users with unwanted content when they are on the go.
Facebook has also been experimenting in the mobile ad realm lately--bringing sponsored stories to mobile and creating a new ad product  for developers who want to market their own apps.