In app purchases and trial runs?

Question

I am building an app for a client that will have 30 days of content for free, thereafter you are required to buy a subscription via in app store purchases.

However,

Answer 1

I think, you are mixing up "content" and "functionality".

You can deliver content items (i.e. an magazine issue) for free or user has to pay for it — so the first n issues, or all issues in a certain timeframe, can be free, while the others need to be paid. But if an user purchased an content item before, you have to re-deliver it for free.

You can sell functionalities (i.e a search in the magazine's archive) as-well. But you cannot give it to the user for free for a certain time and them make him pay.

So the general rule is: What ever the user got from you — you cannot take it back from them and make them purchase it again.