I just posted in a different thread about vending machines. I did it for 2 years and I think it can be a profitable business if you go about it the right way (I didn’t).
An example would be, you start out with one soda machine, it holds 240, 16 oz drinks, you pay between $0.33 and $0.42 per drink and sell for $1.00 each. You refill once the machine reaches 40% capacity. So each time you fill it you make $0.58 x 144 drinks sold = $83.52 profit, less expenses, but you can deduct mileage and such.
There is a forum out there specifically for vending (not sure if I can name) but it’s full of really helpful people.