Machine tipping

There is an idea on here 'keep the change button' but I propose a more sophisticated and complex system. In a vending machine (thinking specifically of supermarket self-service tills here) the change return tray doubles as the tip tray. So you can leave some change in there and pull the 'tip' lever, depositing said excess change into the bowels of the machine.

Now this change does not accrue to the next customer, or to the location owner, or to the machine owner; rather, it remains the property of the machine. The machine in turn can use it to bribe or tip the people or machines that service it - for example, to ensure it is cleaned more often, or to get itself serviced earlier. Or to get better electricity, or something.

Sooner or later, machines will be bidding online (e.g. refrigerators bidding for electricity, to smooth demand) so let's set up to give them a real advantage. The better machines will draw more tips, and so improve their service, in a virtuous cycle of tippy goodness.