content: this is really it.  You're on FB with your real name. Which is usually reasonably unique. It's a quick and easy and foolproof way for people to "find" you, in an age where email addresses change from one employer or school or internet provider to another, and your inbox is jammed with spam. It also has the immediacy of instant messaging, which, thanks to the bullshit of things like microsoft, skype, and everybody and their brother trying to capture and monetize the service; which essentially, is dirt simple to implement as long as everyone knows how to find the server.  IRC did that, but your grandma can't figure out how to set up IRC or which server she h  3c91  as to find you on, etc.  email should have solved this problem 40 years ago.  The ironic thing is; this is not any new technology on FB's part. This technology (messaging/email) was pre-packaged open source server software 20 years ago.  FB succeeds because of it's sheer ubiquity. None of this other user-profiling and data collection is even necessary, other than as a way to keep the lights on.  But the investors make bank also.