wow, that's very impressive.
- I don't know if you can even get a synopsis of how good or bad a site is doing based on one number. However we know twitter is doing well. :)
Do we?
Facebook and Google are both verbally and visibly reacting to Twitter. That's amazing.
They could pick up the phone right now and say, "We're ready to sell" and sell their company to one or more of the big boys. That's pretty impressive.
Are they profitable? Nope. Are they "getting lean", asking "five whys", measuring the hell out of everything, and other Eric Reis-isms? Probably not.
But there are probably VERY few entrepreneurs on the planet who wouldn't trade startups with @ev and @biz. They are kicking ass.