Michael,

I don't know if this will totally answer your question as to why Facebook and not MySpace but here goes. I asked my son the same question not to long ago. His answer was you have more control on Facebook. On MySpace anyone can see your page and send you messages. So you get bombarded and spammed by people you don't even know. On Facebook they have to know you and be invited as a friend to view your page and send you messages.

Ken

P.S. Which may explain why you received the message "do I even know you?".