Facebook's killer app was being the phone directory. Once upon a time, there were paper mail and landline phones, with a directory where you could look up pret

Facebook's killer app was being the phone directory. Once upon a time, there were paper mail and landline phones, with a directory where you could look up pretty well anyone's address and phone number. That was really useful; it was lost in the email years between letters and Facebook messenger. Since no one got a distributed internet directory to work back then, it's hard to imagine that there will be one in the future. And so we're doomed to Facebook.