I imagine it depends on a lot of different things. If they're both high level artists, like say Kendrick and Jay, then they might not be charging each other. Whereas a new artist trying to get on probably has to pay some kinda flat fee and if they don't release it then it's on them.Makes me wonder how much niggas made off songs that never dropped?
Basically, it's like deciding if you want your money upfront or on the back end. Obviously if you don't think it's going anywhere there's not much point in backend.