Nearly 178 million U.S. Internet users watched online video during  December 2009. Online video viewing continued to reach record levels in December, with 33.2 billion videos viewed during the month, according to a report by comScore.

Google Sites continued to rank as the top U.S. video property in December, delivering 13.2 billion videos, with YouTube accounting for nearly 99% of all videos viewed at the property. Hulu ranked second with more than 1 billion videos viewed, an all-time high for them, and representing 3% market share. Microsoft Sites ranked third with 561 million, followed by Fox Interactive Media with 551 million and Yahoo! Sites with 539 million views.

In December, Tremor Media ranked as the top video ad network with a potential reach of 103.7 million viewers, or 58.3 percent of the total viewing audience.

More interesting Video stats

• 86.5% of the total U.S. Internet audience viewed online video.
• 134.4 million viewers watched more than 13 billion videos on YouTube.
• 44.9 million viewers watched 423.3 million videos on MySpace Sites.
• The average Hulu viewer watched 22.9 videos, totaling 2.2 hours of videos per viewer.
• The duration of the average online video was 4.1 minutes.

Bonus link: Top 12 Sites To Watch Videos That Are Better Than YouTube