More than 181m US internet users watched a combined total of 40bn online videos in January according to data from comScore.
Google sites, driven overwhelmingly by YouTube, ranked top with 152m unique viewers, followed by music video website VEVO with 51m and Yahoo sites with 49m.
With 18.6bn views in January, Google accounted for nearly half the total 39.9bn views, followed by Hulu with 877m.
Despite coming eighth on the list for number of unique viewers, Hulu also scored well for viewer engagement with the average user watching 3.2 hours of video, second only to Google sites with 7.5 hours.
comScore also tracked the number of video ads viewed last month, with Hulu delivering the highest number of video ad impressions at 1.4bn.
Google sites did not make the top 10 list for ads viewed.
In total video ads accounted for 12.2% of all videos viewed and 0.9% of all minutes spent viewing video online.
Looking at YouTube’s new list of channel partners, the top two in terms of unique viewers are music video channels VEVO (50m) and Warner Music (30m).
Gaming channel Machinima ranked third with 23.8m viewers, followed by Maker Studios Inc. with 12.5m, FullScreen with 11.6m and Big Frame with 8.2m.
ComScore also reported that 84.4% of the US internet audience viewed online video, with the average duration of online video standing at 6.1 minutes.