I don't use Twitter - I find it unsubstantial. I can't imagine following anyone or anyone following me. Like, how do you acquire followers - posting geeky jokes or retweeting jokes from others? (etc...)
You can use Twitter in many ways. But I treat it as a virtual town square. Some important info, some gossip & news, and plenty of conversations. People get to know me a little bit, and I get to know some people.