It is clear. It is demonstrable. It is unquestionable. A large organization must centralize its operation. This means that cartridges must be shipped back and forth and out of town for service.
Shipping is a mild deterrent, shipping out of town increases the perception of possible delays.
Besides, technical support for cartridges with service out of town is more difficult. These, and other related factors are reasons why there are no mammoth organizations competing for this business. They can be as low as you want to make them and still be effective. A decent one page flier sent to all schools in your areas is but one example. We can help you create one if you prefer.