YouTube continues to be the dominant platform for online video, according to a study from AYTM Market Research, with about 60 percent of U.S. Internet users visiting the site at least once a week as of March 2013. Of those users, 21.7 percent visited every day, and 27.5 percent visited a few times per week. Only 13.7 percent of Web users surveyed “Rarely” visited YouTube, and only 8.5 percent “Never” did. While more than half of users reported watching video content on other sites at least once a month, Google sites including YouTube made up the vast majority of U.S. online video viewership in terms of unique viewers, videos viewed, and time spent per viewer, according to comScore data from December 2012. Facebook was a distant second in all three categories. Numbers of online video viewers in the United States will grow almost 6 percent this year to reach 182.5 million, with much of the growth coming from mobile.

Online video ad views grew 57 percent year-over-year to reach a record high of 13.2 billion in March, according to comScore’s Video Metrix, accounting for more than one-quarter of all online video views. EMarketer estimates spending on digital video ads served to desktop computers and mobile devices will reach $4.14 billion this year, more than twice the total posted in 2011; by 2017, spending will more than double again to $9.06 billion. Mobile video ad spending will account for $520 million (12.6 percent) of digital video ad spending this year, but grow at a double-digit pace to reach 29.7 percent of total digital video ad spending by 2017. The ad dollars won’t come out of television, however; U.S. advertisers will spend $66.35 billion on TV this year and boost spending by 3.7 percent annually to reach more than $75 billion by 2017.