comScore's video metrix service data showing that 172 million U.S. Internet users watched online video content in April for an average of 14.9 hours per viewer.
YouTube.com, ranked as the top online video content property in April with 142.7 million unique viewers, followed by VEVO 55.2 million, Yahoo! Sites 53.2 million viewers. Facebook came 4th with 46.7 million, while Microsoft ranked 5th with 46.5 million viewers.
Google Sites had highest number of viewing sessions with more than 1.9 billion, and highest time spent per viewer at 286 minutes, or 4.8 hours.
Americans viewed 3.8 billion video ads in April, Hulu generated the highest number of video ad impressions at more than 1.1 billion. Tremor Media Video Network ranked 2nd with 603.2 million, followed by Adap.tv (601 million) and BrightRoll Video Network (460 million).
Video ads reached 42% of the total U.S. population an average of 30 times during the month. Hulu also delivered the highest frequency of video ads to its viewers with an average of 45 over the course of the month.