New data from comScore shows that 183 million U.S. Internet users watched online video during the month of May. YouTube.com achieved record levels of viewing activity with an all-time high of 14.6 billion videos viewed and surpassing the threshold of 100 videos per viewer for the first time.

U.S. Internet users watched nearly 34 billion videos in May, with Google Sites ranking as the top video property with 14.6 billion videos, representing 43.1% of all videos viewed online.

Source: Center for Media Research
http://www.mediapost.com/publications/?fa=Articles.showArticle&art_aid=131990#comments