Ask HN: Does anybody have experience with paid apps on Ubuntu software center?

I work as a software developer and sell an app on the Mac App Store. It's a great experience, and I think that centralized App Stores are the future of software distribution. Therefore I'm interested to hear how App Stores work on other platforms, especially Ubuntu's store. When I searched for more info about Ubuntu Software Center, I can find only marketing copy and a Wikipedia article. Judging from https://apps.ubuntu.com/cat/ most of the software seem to be free and open source apps.

Does anybody have experience selling apps for Ubuntu? Is the market big enough to make a living?