By M. Christian

YNOT – Roughly 180 million internet users in the U.S. watched 36.6 billion online videos in May and more than 10 billion of those videos bore advertising, according to data released by analytics firm comScore this week. The advertising figure broke the 10-billion mark for the first time and represented a 117-percent year-over-year growth rate, comScore noted.

According to comScore’s figures, in May Google-owned video sites — led by YouTube — caught the most eyes with 151.7 million unique viewers, followed by Yahoo!-owned sites with 57.8 million, VEVO with 48.3 million, Microsoft-owned sites with 44.4 million and Facebook with 44.3 million.

Nearly 36.6 billion video content views occurred during the month, with Google sites generating the highest number at 17.6 billion, followed by Hulu with 888 million and Yahoo! sites with 845 million. The average viewer watched 21.9 hours of online video content, with Google sites (7.7 hours) and Hulu (4.2 hours) earning the highest average engagement among the top 10 properties.

Though Hulu ranked tenth in total visitors for the month, it came in first in number of video ads delivered: more than 1.6 billion. Google sites in the aggregate followed with nearly 1.4 billion, BrightRoll Video Network with 1.1 billion, Adap.tv with 966 million and TubeMogul Video Ad Platform with 897 million.

Time spent watching video ads totaled 4.5 billion minutes, with Hulu delivering the highest duration of video ads at 725 million minutes. Video ads reached 52 percent of the total U.S. population an average of 64 times during the month. Hulu delivered the highest frequency of video ads to its viewers with an average of 56, while ESPN delivered an average of 29 ads per viewer.