Money for nothing, or the EU case Apple/Spotify

About five years ago, I noticed that someone was paying about 10 euros a month for Spotify through an Apple account, whereas a monthly Spotify subscription was about 8 euros. My first reaction was: why would someone do that? Why pay 30% more monthly via Apple, if you would not have to pay this extra 30% if you got a subscription directly via Spotify? A possible answer is that the user was not aware of the possibility of getting the app directly via Spotify, instead of via the App Store. Apple prohibited Spotify to inform consumers about the option to get the app directly via Spotify and save at least 2 euros a month (>24 euro per year). The case centers around this practice, Apple’s prohibition to Spotify to inform, which is qualified by the Commission as “imposing unfair trading conditions” cf. Article 102(a) TFEU. Apple was fined €1.8 billion by the Commission.