> On the second matter, it really is. The layman perception of a contract is usually a formal document that needs to be signed, whereas in no legal systems that I know of are these actual elements of a contract. In most legal systems a contract is a much broader concept: a private agreement between two parties, with the main defining elements being offer, acceptance and consideration. Most if not all trade transactions are contracts, they include the main elements.

Note the layman perception wasn't why I was doubting this; I'm aware not all contracts are that formal. The reason was I don't know if this is considered a sale or not, and whether other principles apply in that case (like first sale doctrine) and if they might somehow override this.