As mentioned in Cynopsis Digital, here are the top sites adults used to view video content online in 2006, from Piper Jaffray. The numbers represent the percentage of respondents who said they viewed video on these sites:
YouTube 43.5%
TV Network Sites 41%
Google Video 26.5%
MSN Video 24.5%
Yahoo! Video 22%
MySpace 16.5%
AOL 13.5%
Other 17.5%
[image used with permission from Creative Commons by Johan Larsson]