by U.S. Market Share of Visits (%), March 2011
Source: Experian Hitwise
Facebook 64.2%
YouTube 19.6%
MySpace 1.4%
Yahoo! Answers 1.2%
Twitter 1.1%
Tagged 0.8%
myYearbook 0.4%
Linkedin 0.4%
Mylife 0.4%
Club Penguin 0.3%
Take a look on the difference between YouTube and Twitter and Linkedin