Apple doesn't offer promotional codes for in-app purchases. What's the best way to let users try the features or content unlocked by in-app purchases for free, while complying with Apple's Developer Guidelines?
The idea is to allow a special set of users (reviewers, key fans, etc.) to access the content or features offered as in-app purchases without paying.
Examples of apps that worked around this limitation would be much appreciated.
Something like shareware? An app, that has a subset of features enabled until in-app purchase? Apple allows it now.
As example. We've a puzzle game, that has 12 difficulty levels. 4 or 5 of them are available for free and others are unlocked after in-app purchase.
You could submit a version of your application that has all features unlocked by default.
Submitted apps have a publish date that you can set when you submit (and I believe you can change this on the fly as well) you could simply prevent the app from being published in the App store but still be able to give promotional codes for it.
You can let them try, say Level 1, of a game and log that in NSUserDefaults.
This way you can let them use premium features for some n number of times before asking them to pay for it.
Though, a smart user will delete the app and reinstall it -- basically getting rid of the NSUserDefaults. Not sure how to avoid that.
I'm working on this now.
What I'm doing is I generate a random code/guid and store that on my webService's DB. Then give that code to who ever you want. They enter that code and it calls the web service passing the code, and device UDID. The webService returns another code indicating if that promocode was valid. If valid then the app will add that purchase to NSUserDefaults or Core Data (however you keep track of purchases).
If you don't have a server up and running (say the content is already in the app bundle) and you don't want a server would require you making an algorithm to generate keys that your app validates. However this is far less robust. Using a web service allows you to prevent 1 working key from being distributed between all users, as you can tie 1 promo code to 1 device.