Why Twitter Users Aren't Using Google Plus:
"Google Plus has been, by some accounts, the fastest growing social network in history. New numbers indicate, though, that traffic to the site is dropping fast after initial interest. Personally, I find myself more drawn to it every day, because I get so many responses when I post things there. (Disclosure: that could be in part because Google recommended me as a user there, meaning I have twice as many social connections there already as I have on Twitter.)"