I'm a salesman by trade so that's why I see it that way.
That's called a monopoly.
If you are the only one providing a desired service, the urge and need to sell is lowered.
If you are the only baker in town, you are automatically the best baker in town. It has nothing about your quality. And if more bakers open up bakeries, you will have to sell the attributies of your bread and pastries or risk losing customers. If you don't ming losing certain customers,then you don't have to change nor advertise.
But if you do..
Same goes for DMing.