And after all this, Twitter still does not have a viable business model.
...more pertinently, App.net didn't have one either - and they had an open API, charged real money and did all the things HNers' idealized version of Twitter would.
Either:
It is cool. So we must use it.
Or:
Everyone else is using it so we must use it too.
Seriously:
140 characters? Feature?
Everyone can read everything? Feature?
The two biggest technical "features" of twitter can be arrived at by dumbing down either google+ or facebook 98%.
I wouldn't use Twitter if it was limited to people I already know, for instance.
On things like Facebook, discussions are mostly between friends or "friends of friends", with no chance of an outside opinion, for instance.
These are ultimately people they wouldn't choose to follow the conversations of at all, given the choice.
For me Twitter was like starting with a clean slate. I just follow the people I want to follow, basically no 'friends', just interesting people.