“… Publishers who have chosen to hand over their entire communities to Facebook are likewise choosing to give up the entire value of their community. What this means is that they no longer have any data on loyal commenters, and no email addresses, which means no ability to communicate with them again. They’re no longer your users, they’re Facebook’s.
You’re giving a huge strategic and valuable asset to Facebook. They understand the inherent value of comments and community, and are attempting to take it out from underneath publishers before they even realize what’s happened. And we’re back to where we started—publishers don’t quite understand the value of their communities yet.”