• by Mark Walsh  @markfwal, June 15, 2010

The latest buzz around Facebook has been its growth as a video hub in its own right. With a monthly audience of 41.3 million viewers, the social network now ranks as the Web's No. 5 video property, according to comScore. Facebook also says more than 20 million videos are being uploaded to the site each month and more than 2 billion are being watched.

Given the growing video audience and usage on Facebook, how does video advertising actually perform on the site? A new study by video analytics firm TubeMogul found that video ad units on Facebook generally had higher engagement rates and lower cost-per-view than comparable stand-alone, display video ads on third-party sites.

The study presented at the OMMA Video conference in New York Tuesday looked at four types of video ads on Facebook: its official sponsored video ad placement that appears on the right side of a logged-in user's home page; in-banner units in applications; interstitials in apps and games on Facebook; and video ads that users watch in return for earning virtual currency in games to buy virtual goods to accelerate game play.

TubeMogul then compared the performance of 25 major video ad campaigns and 60 million views across the Facebook ad units with the same ads in click-to-play video ad units on other sites, based on criteria including viewing time, cost and clicks per view. Brands included Symantec, Microsoft, Hyundai and 20th-Century Fox.

Overall, it found that completion rates for Facebook ads were roughly 5.5% to 9.5% higher than identical videos run in display units on outside publisher sites. Completion rates for Facebook's virtual currency and app in-banner video ads were both above 40% compared to about 25% for in-banner video ads on other sites.

The Facebook virtual currency -- or in-game -- video ad also had the longest average view time, at 54.7 seconds per view, followed by the Facebook in-banner, at 48.6 seconds, the third-party in-banner, 39.6, and the Facebook interstitial, at 11.2. TubeMogul co-founder Brett Wilson noted that the interstitials had the shortest views because people don't like the auto-play ads and tend to skip them. They are also typically shorter than other kinds of video ads.

Not surprisingly, viewers also were more likely to share videos in Facebook's virtual currency and app in-banner ads with friends on Facebook or Twitter than video ads on other sites. The social-sharing rates for the two Facebook formats were 1.5% to 2% compared to less than half a percent for outside video ads.

The click-through rate on the virtual currency ad was also highest, at 5%, versus just over 3% for video display ads on third-party sites. And when it comes to pricing, the virtual currency ads also shaped up as the best buy, at 30 cents on a cost-per-view basis. That compares to $5.27 for Facebook app in-banner ads, $1.06 for Facebook's sponsored video unit, and $1.07 for stand-alone video ads on other sites.

"So the video in social game unit looks really promising and appears to have a lot of bang for the buck," said TubeMogul's Wilson, highlighting the monthly audience of 70 million for the popular FarmVille game on Facebook. But he warned that marketers should be careful in social game video ads to focus on unique viewers rather than views. That's because "some game publishers break the rules and let gamers click play on a video [ad] multiple times to rack up points," he said.