Replace the paper receipt with a digital receipt. The digital receipt is trackable, does not form a messy bulk in your wallet, doesn't pollute and can represent a sale with much more detail. The digital receipt will be issued to a mobile app by the Store.
The User will benefit with: financial metrics of purchases, no more messy paper bulks in wallet, extra detail on items, item suggestions based on previous purchases, special promotions and loyalty programs.
The Store will benefit with: Not spending on paper, ink and printer for receipts, extra detail in who purchases what, loyalty programs and directed marketing (special promotions, for example: a User likes Coffee a lot, the store knows this because of the records on his account, the Store can create a special offer of Coffee for that customer).