When talking with potential customers, extol the virtues of dealing with your company. If you are a large contractor with a large fleet of equipment, you might point out that there is no excuse for not showing up on time (if enough snow falls soon enough to allow you to complete the plowing in the allotted time frame). You probably have mechanic on staff (or readily available) to get breakdowns fixed quickly so that the equipment is back up and running in short order. You may have a full time dispatch team to insure that ‘special requests’ can be addressed in a timely fashion.
For small contractors, sell the fact that you don’t have a large number of customers – so that every customer gets “personalized service”. You don’t have to keep track of a large contingent of trucks, so you always know where everybody is working. Personalized service means that you care about that customer’s needs, almost exclusively.