Google's youtube continues to dominate ComScore's list of top video content sites, ranking first in both total number of visits and the average length of stay.
According to the report released by digital market research firm ComScore Inc, 174 million unique US viewers watched online video in March for an average of 14.8 hours per viewer.
Out of these 174 million viewers, Google sites led the list with 143.2 million visitors, driven mostly by youtube.
Google was followed by AOL and Yahoo, with 57 and 56 million viewers respectively.
Google had 1,971 million total visits, as opposed to unique visitors, eclipsing the 284 million and 267 million hits that AOL and Yahoo received respectively.
Microsoft came fourth with 53.1 million hits and VEVO came in fifth with 52.6 million viewers.
The report states that US audiences watched 4.3 billion video ads in March. Amongst these 4.3 billion ads, 1.2 billion were generated by Hulu alone, closely followed by Tremor Media Video Network and Adap.tv with 804.3 million and 553 million views respectively. BrightRoll Video Network came fourth in the list with 398 million views (http://tech.fortune.cnn.com/2011/04/13/comscore-google-rules-the-tube/?section=magazines_fortune).