Facebook videoFacebook continues its head-turning upward trajectory in online video, firmly taking over the second place spot to Google sites (YouTube) in comScore’s latest report on online video in the US released today. The data for August 2010 shows that the social networking site delivered 243 million video streams—or as they call them ‘viewing sessions’—to an estimated 58.6 million unique viewers that month. Last August Facebook barely made the chart, coming in at number 10 with just 24 million viewers.

It was enough to see Facebook leap over Yahoo! sites, which is now in third place with 229 million viewing sessions to 53.9 million viewers. Music video powerhouse VEVO isn’t slacking either, serving up 205 million sessions to 45.4 million viewers.

The overall consumption numbers for online video show steady growth once again, with 178 million U.S. Internet users watching online video content in August for an average of 14.3 hours per viewer. That’s about an 11% year over year growth from last August in terms of total viewers.

Full chart below:

comScore online video - august 2010

Facebook is far and above the largest social network site with over 400 million users and counting, but for many of its early years video was largely ignored by the company’s developers. Instead third-party applications like Slide’s FunShare app did most of the video delivery. And while it still hasn’t reached the saturation where it can be the default video search engine that YouTube is, there’s just no escaping the fact that now there’s a whole lot of video getting watched on Facebook.

Hulu Remains King of Video Ads

With heavy viewership numbers come increasing ad consumption, and the August report shows that Americans viewed more than 3.8 billion video ads in August. Top dog Hulu served up the highest number of video ad impressions with 790 million. Not only that, Hulu delivers not just the reach, but the frequency, serving an average of 30 over the course of the month—the highest frequency of any video ad network.

BrightRoll served up 469 million ad views, but at a frequency of only 7.2 ads per viewer. And in the game of video advertising it’s all about reach and frequency, so no wonder content creators are gushing over Hulu’s generous CPMs right now.

One final note, the duration of the average online content video is now at 4.8 minutes. Remember when this was 2.7 minutes not too long ago? Call it the ‘Hulu Effect’, or better bandwidth, or more longer form content, but either way the US internet audience is getting used to kicking back on their laptops a little longer than before.