The issues I have with App.net is that their claims of "we won't screw the user" don't really have any legs to stand on. No company starts out wanting to screw users. But when it comes to turning a profit sometimes you have to put users second. There's nothing built into App.net's model that would prevent that.

Federation bakes that into the model from the beginning. So they're making core claims that aren't built into their core model.

I'm happy to pay for online services like App.net but I wish their messaging would have more sustenance.