If you don't have a lot of followers, twitter is private-ish. There's a difference between a founder tweeting something and a posting on the official company blog, for example.
My twitter feed is so private I only have three followers: me, myself, and I. My wife doesn't even follow me. I don't think she even knows I have a twitter account. It's all very hush-hush.
I should send out more private celebratory tweets....
