Some 25 billion online videos were viewed during August in the US, according to the latest figures from digital analyst comScore.
This was an all-time high figure and Google sites accounted for more than ten billion of the viewings.
Earlier this month, Web TV Enterprise published a white paper showing how the popularity of online video ads has grown considerably over the last two years.
According to the report, online video advertising has put itself "firmly on the map" as an autonomous form of marketing.
The comScore data, derived from the company's Video Metrix service, found that 161 million US internet users watched online videos during August, highlighting the potential audience for advertisers.
Google sites - mainly thanks to video sharing resource YouTube - accounted for 40 per cent of all videos viewed online, while Microsoft sites and Viacom Digital ranked second and third with 2.2 per cent and 2.1 per cent of the market share respectively.
Hulu accounted for 1.9 per cent of the market, with 488 million online video viewings.
