[Charuru]

I'm always leery of a startup based on a platform like this, because Facebook can easily easily take the ground out from under you.

There's also no early mover advantage or network effect (unlike say, admob), so if facebook chooses to implement this it would be fatal.

[naz]

Facebook made status updates public but it didn't kill Twitter. I think everyone overestimates Facebook's ability to kill companies.

[grasshoper]

Twitter is all about asymmetric 'relationships'. You can follow whomever you want. This makes it fundamentally different from Facebook.

[Charuru]

Twitter has network effect.