More people viewed video ads at Hulu than at any other Web site last month, according to stats released yesterday by ComScore.

Out of the 4.3 billion video ads that U.S. Internet users watched in March, 1.2 billion of those were at Hulu, making it the top site for video ad impressions for the month. Video network Tremor Media was next on the list with 804.3 million ad views, followed by video marketplace Adap.tv with 553 million video ad impressions, and BrightRoll Video Network with 398 million.

Internet users spent a total of 1.9 billion minutes watching video ads last month, ComScore said. Out of those, Hulu was the top property, delivering 520 million minutes of video ad viewing. Overall, video ads accounted for 12.7 percent of all ads viewed online in March, while the average video ad ran for 24 seconds.

ComScore's data for video ads includes only streaming advertising and not other types of video ads, such as banner ads or homepage ads.

Among sites offering online videos, Google again took the top spot, due mostly to video viewing on YouTube. Overall, Google sites saw 143.2 million unique video viewers in March, according to ComScore. Google also captured the largest amount of time that each person on average spent watching online videos at 276 minutes, or 4.6 hours.

Google's top ranking was followed by AOL in second place with 57 million video viewers, Yahoo with 56.4 million, and Microsoft sites with 53.1 million. Hulu just managed to make the top 10 list with 27.5 million video viewers. Overall, Web sites offering videos grabbed 174.3 million unique viewers in March, who each spent an average of 889 minutes, or almost 15 hours, watching online videos.