Amazon was recently granted a patent that is a bit peculiar. Amazon might one day launch what is described as “an electronic marketplace for used digital objects”. This includes digital books, music, movies and applications, which users will be able to sell to others, presumably getting back all or a fraction of the money originally spent on it while giving Amazon a cut for providing the service.
It means that a user will be transferring the right to access it over to another user in exchange of a fee. They don’t mention if selling apps, music, video, or whatever back to Amazon itself would be an option. It may just be to other users.
We also don’t know if prices of content will be fixed, or if users will be allowed to set them by themselves.
Source Phone Arena