Our iOS app is a (free) utility app that offers a kind of "private" social network for tennis clubs.
For monetization purposes, we have considered adding Amazon affiliate links in a native way to the app, i.e. not showing banners but instead adding helpful links triggered by native buttons in the app. Example: When creating a tennis court booking, we have a button that says "Already bought tennis balls? We recommend: [button that triggers an affiliate link]".
However, in section 3.1.1 (In-App Purchase) of the App Store it says:
If you want to unlock features or functionality within your app, [..], you must use in-app purchase. [..] Apps and their metadata may not include buttons, external links, or other calls to action that direct customers to purchasing mechanisms other than in-app purchase.
Does the above scenario violate the App Store Review Guidelines in this or another section?