The principle is that the music somehow increases sales, the business gets a financial benefit from playing the music, therefore that should be shared. I get that. There are several problems with that, though – what if the business isn’t getting a financial benefit? A radio in a workshop won’t increase the amount of repair work that workshop gets.
Secondly, why do profits have to be shared? If I sell a bike, I get money from that. If the purchaser then goes on to use it in a multi-million pound advertising campaign or something, making him a lot of money, do I deserve a share of that money?
Does playing music in a shop lead to decreased sales elsewhere for that artist? I’d guess the opposite – in fact there’s a case that the business is owed money by the record company for promoting their artists.