About twenty-seven years ago, when I was in engineering school, I took a course in marketing. This was at the University of Cincinnati, and the professor was a man by the name of Robert E. Dillon.

http://www.library.umass.edu/spcoll/umarmot/?p=979

Anyway, he told us about something called a “Kadoozle Store,” which had been attempted back in the 1930’s. It was apparently not a success, and has been extremely forgotten– I can’t find anything about it by searching Google. Dillon told it, more or less as an exercise in “pushing the limits,” and it was therefore the kind of thing that only an expert would know about. Anyway, the idea was that the Kadoozle Store worked like a coke machine on a larger scale, with various canned goods, each in their individual racks, and motorized levers causing them to drop to chutes or conveyor belts.

First one took a hand-held paper-tape punch, and walked around to wall displays showing the various goods. One plugged the punch into sockets associated with each picture, and that caused the punch to punch a code into the paper tape. Think of it as the equivalent of a bar-code scanner by more primitive methods.

One then took the tape to the checkout counter, where it was fed into a totalizator machine to compute the bill. Once that was done, and the groceries were paid for, the clerk would insert the paper tape into a reader device, which would activate the levers of all the various racks, and the various items would come spilling down the various chutes to a central collection point.