Ok, so what is Twitter and why should you care? First, let's start with what it isn't. Twitter is *not* about micro-blogging. Yes, it is described this way - yes even by it's founders. But they have also admittedly publicly that much of the innovation on Twitter has happened in the user base - the convention for retweets (RT), for example, came from the user base. For those of you who are new, RT is just a way to a convention for sharing a message from someone you follow to your own followers. It's sort of citation plus recommendation plus message all wrapped in a little two letter acronym.