I am thinking of building an app where I will provide some services to users, and users use the services when they are under subscription.
I want to be able to reward user when they did what I want them to do, by providing, for example 50% off from their subscription for the period(every week). This is something I cannot do currently, because there seems to be no sdk support at all.
Question is, is it possible to let user pay through external payment? Once they subscribe, and login, my app would treat them as if they are subscribed from itunes, only i am now able to discount my user.
I understand I am not allowed to provide any link or button to the external payment, what about just a text asking user to search on the web?