These are not centralized solutions in the way Facebook is. If I use Gmail does that force you to use Gmail? Great services like Gmail only became possible bec

These are not centralized solutions in the way Facebook is. If I use Gmail does that force you to use Gmail? Great services like Gmail only became possible because SMTP isn't tied to a particular proprietary service. Individuals can use the service that's most appropriate for them. For some people, that's Outlook, for others, a webmail provider. Competition works. What we really need is a system that crosses social-networking-service providers in the same way that SMTP broke down the barriers between various mail systems.