Right but a receipt of what? A receipt, evidence, or proof, that a transaction took place. But a transaction of what? One party got money. What did the other party get? A proof that s/he paid the money. For what? For the proof that s/he paid the money ... for the proof that s/he paid the money for the proof that ... LOL.

Makes me think that I should make an NFT out of Brooklyn Bridge. That might gain lots of fame and thus lots of value?