I asked my g'dad why he went to service station A when service station B was cheaper. His reply; service station B doesn't wash my windscreen. That has stuck with me.
Started my own business based on service. My business had products you could buy at chain stores, but we provided one thing they didn't - service. From service we had repeat customers. From repeat customers we got 'word of mouth' customers and the business kept growing. Turnover was over $700,000 when I sold.