I know it is possible to include an affiliate token in an App Store URL, or in a SKStoreProductViewController object. But is it possible to do the same when a user buys an in-app purchase?
It doesn't seem to be possible to link to an In App Purchase, so you cannot install your affiliate token via that method. Although once someone has clicked your affiliated link (say to an app, song or movie) on a device, it looks like you can be credited for In App Purchases.