I love reading about interesting business models such as this. A similar one I've read about before is vending machines. Apparently a well-run vending machine b

I love reading about interesting business models such as this. A similar one I've read about before is vending machines. Apparently a well-run vending machine business (ignoring labor costs) can easily achieve 50-100% ROI per year per machine. The vending machine owners don't usually have to pay for the electricity of the machine and each machine only costs $2-3k. Maintenance/restocking has relatively low labor requirements and the stock itself is so cheap it's almost a negligible cost.