Medic-aid Vending Machines

A cold call is where a sales person tries to make contact with a potential customer, having never had contact before. The success rate of the cold calls can be pretty low, so trying to use the advantages of a prior relationship is preferable. For example, if you have a friend who works at a prime location and they put in an initial call, you are now making contact with some prior link in place.
One Quarter At A Time

An aspect of this business that you should consider is profit margin versus brand awareness. Gumballs, for example, have a very high profit margin, so that on a per unit basis they are a great investment. Coke or Pepsi, on the other hand, have a tighter margin, but you get the benefit of selling a product people know about, which in turn impacts your sales.

Shelf life is an important part of the equation as well, because spoils cut into profit. Let's say, for example, that you are selling peanuts from a particular vending machine, with a profit margin of fifty cents per unit. If you can keep your spoils below ten percent, you're doing great; above that, you aren't making much money.
A Business With A Plan

The bottom line is, well, you need to have a bottom line. The vending machine business has to be viewed like any other business, with income measured against cost to assess profit. Yes, the business is simple compared to many other models, but anytime you put money into a venture, there is risk involved.

Finally, the single most important aspect of your business is maintenance. On a different day at that same grocery store, the man came in and the bird said nothing. Keeping fresh stock, in a machine that works, is simply a non-negotiable aspect of making your vending business work.