• by Mark Walsh  @markfwal, January 13, 2011

Mobile activity continues to ramp up on YouTube. The video hub revealed this week that mobile video plays tripled during 2010 to 200 million a day. The site highlighted the milestone in connection with announcing the addition of Vevo's extensive catalog of music videos to its YouTube app for Android.

That should help boost the site's mobile viewership even further, given the popularity of Vevo online. The music video site in November jumped up to third place in comScore's ranking of sites by video views, trailing only YouTube itself and Yahoo. Its monthly audience of 50 million unique visitors put it just ahead of AOL and Viacom Digital.

In addition to adding Vevo content, the latest version of YouTube's Android app will also add pre-roll ads before videos. "This not only expands distribution opportunities for partners like Vevo, but also opens up more revenue to partners distributing their content to mobile. Although we've tested ads on mobile over the years, this is our largest step in mobile monetization to date," stated a YouTube blog post by Andrey Doronichev, the site's mobile product manager.

Earlier this year, YouTube said tests of mobile ads -- with brands ranging from L'Oreal to Land Rover -- showed strong results in click-throughs, user experience, and brand awareness. Last year, YouTube began selling banner ads on a full-day basis on its mobile site as an extension of home page ads running on YouTube.com.

The Google-owned video site says its next step is to let partners run ads more broadly across other platforms beyond Android native apps. YouTube in July unveiled a revamped mobile site, which it subtly touted in a promotional video as a superior alternative to the pre-installed Apple-created YouTube app for the iPhone.

Only about 10% of the 229 million U.S. wireless subscribers 13 and over watch video on their phones, according to Nielsen data. But of the 22 million mobile video viewers as of the second quarter, almost half (9.6 million) watch YouTube. That total, while only a fraction of its online audience, was big enough to make YouTube the top mobile video channel in 2010, according to Nielsen.