Comscore today revealed that the popular social network YouTube has reached 100 million viewers. In total, internet viewers have viewed 14.8 billion online videos in January 2009 alone.

According to Comscore: “YouTube led the growth charge, accounting for 91 percent of the incremental gain in the number of videos viewed versus December, as it surpassed 100 million viewers for the first time.”

Google continues to surpass others in terms of online video viewing with a 43 percent market share. Of that, YouTube accounts for 99 percent of the videos viewed. Fox Interactive Media account(3.7 percent), Yahoo! Sites(2.5 percent) and Viacom Digital(1.9 percent) are trailing behind by a wide margin.

In January 2009, 147 million U.S. internet users watched an average of 101 videos per person.

Are these numbers what you expected? Where do you see online video growing from here? Leave your thoughts in the comments below.