Presale your saas product throught nft.

could we sell an NFT to the user, and promise those who get this NFT can use my product forever? and I could sell these NFTs for one or two years' price. so I can presale[funded] by my users.

And the user can exchange this NFT. so the Products can get money at the early stage, and the user could win the NFT price up.

It could be a double-edged sword, do you guys love these ways? if it could implement simply