The only flaw of all this is that vanity ids won't automagically become email addresses for everybody. If I tell my friends to find me at facebook/kilimanjaro

The only flaw of all this is that vanity ids won't automagically become email addresses for everybody. If I tell my friends to find me at facebook/kilimanjaro I want them to message me at kilimanjaro@facebook.com too. They should associate and create 500M email accounts right away and become the greatest email provider on earth.