The Twitter population is a rounding error compared with Web mail or Yahoo Messenger, AIM, MSN Messenger.
Sometimes it’s hard to keep perspective in all the breatheless hype around new technologies. Twitter’s a great case. THis doesn’t mean it’s not valuable now or that it won’t be huge later, but it does mean you should be careful and try to get some perspective on who your customer really is before you double down on the latest early adopter trend. Early adopters try a lot of things, most of which go up in smoke.