the whole twitter phenomenon is just a circle jerk of marketers and internet "celebrities". I doubt if even 5% of their population is "real" people. And even that 5% is nothing more but fanboys who wish to be the future internet celebrities.
I don't know a single "real" person who uses it, beyond that first minute. All of them come away with "WTF is the point".
Sure twitter has marketing power, because all the bloggers have convinced themselves that this is the best thing since sliced bread. But the real world could care less.