Social Media: Average Time Spent

Average minutes per visitor to social media sites.

Facebook (405)
Tumblr (89)
Pinterest (89)
Twitter (21)
LinkedIn (17)
MySpace (8)
Google+ (3)

Does not reflect mobile usage.
World-wide data as of January 2012.
Sources: comScore, The Wall Street Journal,

How much time to you spend on these social media sites? Any ideas?