You can make an NFT pay a percentage of the resale to the original creator. So I can make an NFT such that I get 10% of resales forever: e.g. I make an NFT, you buy it for $20, then sell it to Bob for $40, Then Bob sells it to Mary for $30, and Mary sells it to John for $10, I get $20 + $4 + $3 + $1.