If a company like Spotify sells subscriptions both in the app and on the web, they have to charge 43% more to the in-app purchaser to get the same revenue, even though the user gets exactly the same experience.
I would call that a tax (informally; I know it strictly doesn't meet the definition) and as a customer I would like to know about it.
I would call that a tax (informally; I know it strictly doesn't meet the definition) and as a customer I would like to know about it.