Snapchat bootstraps its social graph on top of the already-existing social graph of "people who have each other's cell phone numbers." Actually learning and typ

Snapchat bootstraps its social graph on top of the already-existing social graph of "people who have each other's cell phone numbers." Actually learning and typing in people's Snapchat usernames is possible but not common. Exchanging phone numbers is already integrated into the social fabric of our society as a step in escalating a friendship or asking for / receiving the opportunity to date someone. It's a somewhat intimate act, and appropriate for a communication mechanism that's basically only used between people who are already friends. Snapchat doesn't have the ability to discover acquaintances / friends-of-friends nearly as easily as Facebook does. I also wouldn't say it "took over messaging." People don't really have actual conversations on Snapchat, they send photos of themselves making weird faces or Twitter-style status updates. New class of thing.