The most popular site was YouTube, whose videos were viewed by more than 135 million users during the month. YouTube reached three out of every four online video viewers, with each person watching an average of 96 videos in the month, comShare said.
"U.S. Internet users watched 31.2 billion videos in March with Google sites ranking as the top video property with 13.1 billion videos," comScore said in a release, adding that number represented "41.8% of all videos viewed online." Far behind in the second position was Hulu, which recorded 1.1 billion videos watched. That figure represented just 3.4% of all viewed online videos, comScore said.
The next sites, in order, were operated by Microsoft, which had 655 million views, followed by Yahoo, 478 million views, and CBS Interactive, 457 million. Trailing with views less than 400,000 were, in descending order, Viacom Digital, Vevo, Turner Network, Fox Interactive Media, and AOL.
ComScore, which measures a variety of online digital usage, said that 84.9% of the entire U.S. Internet audience viewed online videos in March. A total of 135.3 million viewers accessed YouTube to view 12.9 billion videos.
The top video ad network was Tremor Media, which had a potential reach of 96.5 million viewers in March, followed by Adconion Video Network with 81.6 million potential viewers, and Advertising.com Video Network with 80.8 million potential viewers, comScore reported.
Joost Video Network utilized the Adconion Media Group to score a 38% market share of U.S. online video viewers while SpotXchange used Video Ad Network to reach a 19.9 market share.
ComScore said the average length of video views was 4.3 minutes.