This may be a noob question, but does any know how a market like Nifty or any similar nft marketplace actually implement paying a "creator share" or royalty back to the original creator after any secondary market sales? Would this be included somewhere in the actual ERC-721 smart contract itself or are they tracking/disbursing these creator shares another way, some sort of logic layer that's tracking the transactions?
To be clear, I'm talking about a secondary sale within the same marketplace, not referring to any implementations of EIP-2981.