Just how big will the online video monster grow?  So far, the steroids have yet to wear off, and Michael Jackson kept the party going in July.

According to the latest data from the United States, viewing levels are still setting records.  Specifically, in July, more than 158 million viewers watched videos online of some sort, according to comScore.  That population consumed 21.4 billion videos, and the average amount of viewing topped 8.3 hours.

Perhaps the acquisition of YouTube was worth $1.65 billion after all, though nagging monetization questions remain.  The video giant has been pointing to profitable collaborations with major media companies, including the attention-grabbing ‘JK Wedding’ video, a nice iTunes sales driver for Chris Brown and Sony Music Entertainment.  At least systems and sales drivers are in place, though revenues remain quite modest according to executives. 

Others in the ranking include Microsoft, MySpace, Hulu, Yahoo, Viacom, and Fox Interactive Media.

Report by Alexandra Osorio.