Twitter is by far the easiest way to share content with your readers. Also, I'd stay clear of MySpace haha
yes because if you have gmail, you are already connected to all sites that linked to gmail even if you don't sign up yet.
Just because Google is so popular it got so many users unlike Facebook which started from 0 and now at top.
Facebook is popular but I like Google Plus more. Recently, Facebook is vulnerable to spam though I'm very much impress with how they can cope up with it quickly.