The main problem with Twitter is that it's no longer a chat system, it's a broadcasting system, where the broadcasting is done by media stars, sports people, journalists etc.

Unless you already have friends on Twitter, there's basically nobody to talk to. That leaves more than 90% of users tweeting into a void, with no one listening. This is why most Twitter accounts are inactive.

If you're a normal person with friends and family on Facebook, you're better of "tweeting" there, because you are far more likely to get a response.