This is not a programming question per say. Please redirect me to proper place in case this does not fit stackoverflow's guidelines.
I am working on an app where people can consume virtual content (say an ebook) after paying for it. Now the same content (once the user has downloaded it) can be viewed (free of cost) on different devices. In such a scenario, is it mandatory for me to use Google's payment gateway?
As per Google's guidelines (http://play.google.com/about/developer-content-policy.html#payments), for anything which can be used outside the play store (like an .mp3) does not require Google's payment gateway.
Similar question: https://stackoverflow.com/questions/15789246/android-play-store-policy-for-digital-content
In any case, how reading an ebook (for example) different from .mp3 ?