So, it’s “profitable” as long as no one is on the company’s payroll full-time and they stop paying developers for their usage contributions. Basically, App.net has run out of road. There’s no way this service makes a resurgence. Developers weren’t building on the platform with the money incentives intact. Take it away and you really have got nothing.
The user base of App.net will slowly diminish as people gradually stop renewing. At some point, likely not too far in the future, it will get shut down completely.
The ecosystem side of App.net was always doomed, but I want to make one remark about the Twitter-clone aspect of the service. I joined App.net in late 2012 with much chagrin. I posted on App.net about 130 times in total over that period. I’ll write that number of tweets in a week, easily. Kinda sums it up.