Because people are already posting to Facebook, and it provides a lot of excellent scaffolding, including a small comment box that gives friction to large messa

Because people are already posting to Facebook, and it provides a lot of excellent scaffolding, including a small comment box that gives friction to large messages, and little friction to short messages. A bunch of short messages is what I want, which is not something typically someone is going to email. They also want to broadcast it to all their friends in a lightweight way that doesn't clog up inboxes and signals that it's optional knowledge, which an email doesn't.