I kept getting mail about new people following me on Twitter, although I had stopped updating that about the time Wrath of the Lich King came out. So as I wasn't using my Twitter account anyway, I deleted it, to not disappoint people waiting for me to say something there.
I made the Twitter account to test it out, but found that it wasn't something I really enjoyed. I can't express my thoughts properly in less than 140 characters. Plus I have a personal aversion against services that lead people to reveal too much of their private lifes. "Got up", "brushed my teeth", "had toast for breakfast", etc. is an extremely boring, if accurate, way to record our daily existence. And when people try to hide how boring their life is by posting half-naked drunken photos of themselves on Facebook, they only manage to destroy their chances when applying for a job later at a company with a tech-savy human resources department.