According to the comScore Video Metrix service, 182 million U.S. Internet users watched online video content in December for an average of 23.2 hours per viewer. The total U.S. Internet audience viewed 43.5 billion videos.Google Sites, driven primarily by video viewing at YouTube, ranked as the top online video content property in December with 157.2 million unique viewers, while VEVO ranked second with 53.7 million. Yahoo! Sites ranked third with 53.3 million viewers, followed by Viacom Digital with 45.8 million and Facebook with 42 million. More than 43 billion video views occurred during the month, with Google Sites generating the highest number at 21.9 billion. The average viewer watched 23.2 hours of online video content.