I didn't ask my question in a vacuum, I asked it specifically within the context of Reeder 2. Reeder 2 is (as Reeder always was) a premium app, so ads are not a

I didn't ask my question in a vacuum, I asked it specifically within the context of Reeder 2. Reeder 2 is (as Reeder always was) a premium app, so ads are not an option. It is a front end for other third party services rather than something that has its own backend, so charging a recurring fee for the backend is not an option. iOS App Store guidelines rule out other options. Really, the only option that can sustain the costs of the continued development of the application is charging for each major release.