The three legged stool of a successful business usually involves the relative quality and value of the product, after-sales service, and responsiveness/communication with customers. Take one of those away and problems begin to arise, take two away and the business will be in real trouble.
An owner/proprietor can choose how to operate and can utilize practices that do not let them become a victim to outside influences that affect the three legs of the stool. Those practices often include organization, prioritization, and hard work. Problems arise in any business and the effectiveness of how those are handled often determines the success of the business. One thing is for sure, the customers have the final vote.