Outside of Japan maybe, but it's something that would work in that culture. From my last trip to Japan a couple of years ago, I saw vending machines everywhere. In urban areas, there would be one every couple of city blocks in urban areas; I even encountered a few in the middle of park trails in relatively more secluded areas (e.g. more or less the middle of a forest). All these vending machines appeared unattended, but they always had inventory.