Question: If I offer an in-app Non-consumable purchase (say a book, or a song) within my app and then 2-3 months after it has been released I realize that there is something wrong with my digital content, Can I do an update of the digital content? So if I had a digital article as an in-app purchases for $1.99 and sold 1,000 copies, then I realized that I have a spelling error on page 3. Would I be able to upload an updated article that would go out to all the people who bought the article and prevent people from downloading the old copy? If not, how is this situation handled in the real world? I have looked in apples doc, but cannot find an answer. 

Edit: Assume I am using the new io6 feature of hosting the content through apple.

Answer: 
Yes, as a matter of fact, provided that you do a few steps, you can keep track and systematically, efficiently keep track of what is downloaded.

> 1.Yes it's possible. Provided you keep a track of who has bought what pack (ie. keep a bool value as an NSUserDefault), then they will still have access to it (even if you add more stuff/levels to it).
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> 2.It depends what you mean by notified; they will know if they read the update comments when they install the update. Also you could just choose to alert them when the load the app after the update - your call.
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> 3.If you're submitting the code Apple will review it. Just think of it like any other update to an app. 

This is taken directly from here: [Update in-app purchase content for iOS app?](https://stackoverflow.com/questions/7780133/update-in-app-purchase-content-for-ios-app)

After you have updated your content for the app store, you can allow your users to **Restore Purchases** and obtain the updated content!

Overall, have a mechanism to keep track of the version of the in-App purchases' version and then update when needed!

There is always, apple's own documentation: 
[Here you go! :)](http://developer.apple.com/library/ios/#documentation/StoreKit/Reference/SKDownload_Ref/Introduction/Introduction.html#//apple_ref/doc/uid/TP40011851) 

I hope this is clear and helpful!

EDIT:
After checking the user's content version number and finding that it's outdated, you would call the method (by the way, you would probably implement this checking mechanism in your app delegate.

```
[[SKPaymentQueue defaultQueue] restoreCompletedTransactions];

```

This would restore the transactions, but make sure you also need to include the rest of the implementation code!

I assume you know the code to restore in app purchases, but if not, here are a couple good links!

[Restore already bought in-app-purchases on iPhone?](https://stackoverflow.com/questions/7761556/restore-already-bought-in-app-purchases-on-iphone)

<http://www.iosdeveloperguide.com/in-app-purchase-heads-up-to-avoid-app-rejection/>

<http://appotography.com/2011/07/06/restoring-purchases-on-iphone-and-ipad/>
This all depends on how you make the content available to the user. When the user makes their original purchase of the in-app content, where does the content come from?

If it is part of the app bundle, then the only way to get updated content to these users is to submit an update to your app that includes the updated content. When the user installs the updated app, they will see the updated content.

If, upon purchase, the app downloads the content from your server then you can build in a mechanism in your app that checks your server for updated versions of the content. If it detects there is an update, and the user has the IAP, then the app can download the updated content.

Edit: This doesn't cover the new iOS 6 feature of Apple hosted downloadable content.