My problem with App.net is that the user payment is only a means to an end no one has explained yet.
I welcome any competition to Twitter to make them step up their game, though, so from a spectator's view, I couldn't be happier to see App.net succeed. As a hypothetical user, the platform holds no appeal to me. I still remember Jaiku, Pownce and Identi.ca.
I guess my only quibble about App.net is that I've never personally seen the appeal of the micro-blogging/twitter social model. I don't like to "follow" people, and I like to say things to other people in more than 140/256 charters. I believe that there is a generally correlation between the length of people's comments/text and their quality.
I would like to see a more integrated real time feed, i.e the music people listen to, the movies they watch, where they eat so that developers can use it to make recommendations to me. That would be awesome as long as I can have fine grained control over who get access to what information.
I am excited to see if App.net is going to go in this direction.
I don't need another social network. I don't need ads removed from my current social feed. I don't need app.net.
If twitter died tomorrow something else would pop up. That's the nature of the space. We don't need it and so we go where there is less friction. Ease of use, ease of joining, and ease of finding those I care about most. That's all that matters.
I see App.net becoming something much like svbtle. A highly curated space much like a country club where only those willing to pay the entry fee are allowed in.
Cool.
As long as the data is available publicly through feeds and other api's it won't matter too much. It's still blogging, it's still tweeting, but now your participants have been restricted. Not as much as Svbtle but enough to encourage a certain atmosphere.