Reason to exist != mindshare. By that time, big names and whatsnot was on Twitter and you have snowball effect going. And you can observe how the shift goes fr

Reason to exist != mindshare. By that time, big names and whatsnot was on Twitter and you have snowball effect going. And you can observe how the shift goes from sms backed to web and app backed. But once you mostly interact via web and app, the whole thing about 140 characters goes out the window and you basically turn into a cramped "facebook" (or perhaps and RSS feed). At the same time the main innovation was not happening at twitter hq, but in third party apps (Tweetdeck etc) that allowed people more control over just what part of the stream they wanted to pay attention to. Twitter is effectively coasting.