Up until now, iOS developers have been unable to distribute promo codes for in-app purchases, but Apple is now allowing developers to issue in-app purchase promo codes via iTunes Connect.
Apple says that developers can give away up to 100 promo codes for each in-app purchase item, up to a maximum of 1,000 codes per app every six months. That means if you have 10 in-app purchase items, you could distribute all 1,000 codes spread across those 10 in-app purchases.
In the past, some developers have been able to offer free in-app content for promotions via workarounds, but this change is official, works similarly to normal promo codes for redeeming full apps, and is available to all developers with in-app purchase content on the App Store.
I recently ran into a situation where a developer asked me to look at an app, but couldn’t provide a promo code because the content was behind an in-app purchase. Thus, I was not able to explore the entirety of the app without paying for the in-app purchase. Needless to say, this is a very welcomed change for developers and members of the press.