Thomas Vander Wal has made a good point about a flaw of the ‘walled gardens’ like Facebook and MySpace - they break the communications loop.
Inline Messaging :: Off the Top :: vanderwal.net
Many of the social web services (Facebook, Pownce, MySpace, Twitter, etc.) have messaging services so you can communication with your “friends”. Most of the services will only ping you on communication channels outside their website (e-mail, SMS/text messaging, feeds (RSS), etc.) and require the person to go back to the website to see the message, with the exception of Twitter which does this properly.Here is where things are horribly broken. The closed services (except Twitter) will let you know you have a message on their service on your choice of communication channel (e-mail, SMS, or RSS), but not all offer all options. When a message arrives for you in the service the service pings you in the communication channel to let you know you have a message. But, rather than give you the message it points you back to the website to the message (Facebook does provide SMS chunked messages, but not e-mail). This means they are sending a message to a platform that works really well for messaging, just to let you know you have a message, but not deliver that message. This adds extra steps for the people using the service, rather than making a simple streamlined service that truly connects people.