It’s a social graph that’s divided by time zone. I can’t be connected to these people because I live in Europe and so times when I can reasonably be on a phone

It’s a social graph that’s divided by time zone. I can’t be connected to these people because I live in Europe and so times when I can reasonably be on a phone call do not overlap with theirs. Twitter on the other hand... I can be connected with these people and not only can I “catch up” later, but reading Twitter in bed is more socially acceptable than being on a conference call.