For many years, one of my friends ran a very successful one‑man agency. He had a handful of principals and managed to keep the principals and customers very happy. He maintained most of his principals through the years, and after a considerable amount of windshield time, he is now enjoying a very comfortable retirement.
One of the reasons this friend was able to stay in business for such a long time (with little change of his lines) was his philosophy of trying not to burn any bridges. In fact, he was able to get one line back after having been previously canceled.
Another friend ran a large multi‑person rep organization with tens of millions of dollars in sales. One of her tenets was to investigate prospective principals very thoroughly. In several instances it initially appeared that the principal’s products were not a synergistic fit to the agency’s existing lines. However, after a little more research they found that they were already calling on 60 percent of the prospective principal’s customers. After grooming a successor to purchase and run her company, this rep is also enjoying a comfortable retirement.
So the size of your agency really doesn’t matter so much as your commitment to your customers and principals, a good understanding of the products your customers purchase, and knowledge of the industries you service.