Research outfit comScore has released a report showing that 161 million US Web users watched online video in August – the largest audience ever recorded. According to the firm, over 25 billion videos were viewed during the month, and Google accounted for more than 10 billion (39.6%) – no surprise with YouTube in its portfolio. In fact, the popular video sharing site made up 99% of the videos watched on Google sites.

Meanwhile, Microsoft sites had the second most views at 2.2% or 547 million videos served. Viacom Digital placed just behind Redmond with 539 million views. Hulu claimed 1.9% with 488 million views, Fox Interactive Media 380 million at 1.5%, Yahoo 355 million at 1.4%, and Turner Network 299 million at 1.2%. The remaining properties held less than one percent and include CBS, Disney and AOL.

Google sites pulled in 121.4 million unique viewers during August, which breaks down to 82.8 videos per viewer. Microsoft had 54.9 million viewers (10 videos per viewer), Yahoo had 51.6 million (6.9 per), and Hulu 38.5 million with 12.7 videos watched per person.