The reason Twitter succeeded is because of the simplicity of the idea and design. It's simplicity allows it to be whatever the user needs it to be. It can rep

The reason Twitter succeeded is because of the simplicity of the idea and design. It's simplicity allows it to be whatever the user needs it to be. It can replace your RSS feed aggregator, your bookmarks, your facebook, your contacts on your cell-phone, etc., etc. Features get added over time, but they're much more opt-in then opt-out. Meaning, you actively have to seek them out and use them; they're not forced on you. This means that the base product is still the same as it has always been; they're not, as 37 Signals would put it, dying with their user base. In summary, Twitter serves many purposes and it does it in a fashion that it doesn't get in your way.