A report released by comScore pointed out that, driven by Youtube, in March 2007, Google Video accounted for 17% of the US online video market share. In March, Americans consumed a total of 7 billion online video streams. Google ranked first with 1.2 billion streams (16.7% market share), Yahoo ranked second with 434 million (6.2%), followed by Fox with 431 million (6.0%), and Viacom with 260 million (3.7%).