There is a very interesting infographic making the rounds on how many college and university faculty are using social media personally and professionally.
Personally, I find it a bit hard to believe that the numbers are that high. And, unfortunately, the source of the data, while indicated, cannot be inspected!
I think it depends on how one defines social media. Is using material (text or graphics) from Wikipedia considers using social media? Is signing up for a Facebook or Twitter account, but never really using it, considered having used social media?
If yes, then OK, I can see the high numbers. But I know so many people who have signed up for social media sites, but never use them. Although, I do admit that they may use their accounts some day