not sure how much of radio works anymore but, in the 90s, Canadian radio stations were complaining about how they need to buy music playing rights in large blocks, which is why listeners would complain about hearing the same 15 songs over and over, as it was "cheaper" to get 15 songs at 20-odd plays per day than 100 songs for 2 plays per day 😕

variablepulserate.10centuries.org.