comScore released its ranking of online video sites among the U.S. Internet audience for July 2010 this week, and as you might expect, YouTube continues to lead by a very wide margin.  You can see the results in the chart below:

According to the report, 178 million U.S. Internet users watched online video in July 2010 with an average of 14.7 hours watched per person.  The monthly rankings didn't change significantly in terms of market share from previous months, but Facebook did climb one spot to the third position in the ranking list, above Microsoft sites.In total, 84.9% of the U.S. Internet population viewed online video in July 2010.  The average online video was 4.8 minutes long.  Interestingly, online video ads accounted for 9.8% of online video content viewed in July 2010 but made up just 0.9% of actual online minutes spent viewing online video content during the month.Of sites known for publishing short-form video content, YouTube by far surpassed all other sites in terms of viewer engagement (i.e., the length of time users actually viewed content).  Hulu also ranked high in terms of viewer engagement, but Hulu is known for publishing long-form video content, so this is to be expected.It's an exciting time of growth for online video, and it's very interesting to keep track of viewer statistics related to online video.  Will another site ever be able to compete with YouTube for short-form video content?  It's interesting to consider what's next for online video.  What do you think?