Google was the top US streaming video property in March, with 57.4 million unique people streaming ("streamers") and 1.2 billion video streams initiated, according to the comScore Video Metrix rankings, reports MarketingCharts. YouTube.com drove the lion's share of video streaming activity, with 53.5 million unique streamers and 1.1 billion streams initiated.

Americans viewed more than 7 billion video streams online, led by Google Sites with 1.2 billion (16.7 percent share of streams).

Yahoo Sites ranked second with 434 million streams (6.2 percent), followed by Fox Interactive with 421 million (6.0 percent) and Viacom Digital with 260 million (3.7 percent).

More than 126 million Americans viewed online streaming video in March. Google Sites also captured the largest streaming video audience with more than 57 million unique streamers, followed by Fox Interactive Media with 47.4 million and Yahoo Sites with 34.5 million.

MarketingCharts has more data here.