Of course I'm not surprised. ... Many people are using social media in new and innovating ways. I personally don't have an account, because I think its too, risky and poses privacy issues.
For business owners and people who are into networking, its a great tool. I was listening to a social media webinar this week and it presented social media as an astounding inexpensive way to have publicity without spending loads of money. Think of sites like this and all the advertising that you see on the sides, top, bottom... people who visit although they aren't frequent to blogging or commenting buy or at least go to the pages.