From vending machines to smart contracts

Parts of the trend towards smart contracts are advances in vending machines. Indeed, a vending machine is a very ancient kind of smart contract, supposedly going all the way back to coin-operated holy water dispensers in Ptolemaic Egypt.

Touch screens allow some newer vending machines to present a user interface like that of a web site or catalog, and newer robotic mechanisms allow the goods to be dispensed more carefully (and thus allow a wider variety of products to be dispensed). If you haven't yet used one of these newer machines here's a good video:



It's important that the machine be as fair as possible to avoid either the vendor or the customer being cheated. But it's tricky. "[T]o prevent the thing snagging and you getting ripped off," Motorola's machine is designed so that "your card is only charged when the sensors detect you removing it from the bin."

There's a flower-vending machine where you can either buy fresh flowers from the machine itself or order flowers sent somewhere.

There's a machine that loans soccer balls. The user interface is your cell phone instead of on the machine itself. The balls are tagged with RFIDs, a primitive form of proplet, so that the machine can tell when you've stolen a ball (or at least when you've removed it out of the allowed area of use) rather than returned it. The machine also keeps a social register of soccer players to help you find somebody nearby to play with. This is moving us far from the traditional vending machine and towards a far wider variety of automated transactions heretofore enforced by contract or property law rather than computer protocol.

Japan, as a low-crime and gadget-loving country, fields machines selling a wide variety of products and services. There's a refrigerated locker where you can store your groceries and continue shopping and a machine where farmers can put in money and polish their rice. Some machines take 10,000 yen notes (about $80). Some parking machines place bars under or in front of the car that prevent the car from being removed from the spot until the fee is paid.