How much growth has Twitter lost because of all the time it’s unavailable? I have never engaged in sustained use of a web app that is down this much – I can imagine large numbers of other people just walk away and never come back. Everybody says Evan Williams has struck gold in this wildly succesful new service – but I’m sure he knows there’s a real risk of that never proving true do to constant service problems. Good luck to the Twitter folks – I sure wish the site was up!