Try to vacation in Italy: Consumers are obliged to get an invoice, businesses are obliged to provide one. Including cryptographic signatures (but without the big-list-of-article-numbers and centralized signatures craziness). The financial police are allowed to stop customers within a certain distance of a business and ask for the invoice for their purchase. If the customer cannot provide one, the customer and the business are fined heavily. That's why the business owner will get very angry with you when you (as a clueless tourist) immediately chuck the invoice in the bin, because why would you keep the invoice for a pack of gum...