If you take a close look at the companies that consistently have the highest approval ratings, they seem to have a few key things in common when it comes to customer relations: value, quality, and service.
Value: Customers are initially attracted to what a company is selling based on low prices for what they want. Large companies filling orders wholesale or individual consumers buying clothing will often compare prices from several sources before deciding to purchase, and sale advertisements are based on the concept of value for the money spent. Wal Mart's entire business model rests on this type of relationship with the customer.
Quality: The quality of the good or service a company provides is what keeps consumers coming back for repeat business in the future, and what causes them to give positive references through word-of-mouth recommendations to friends, relatives and associates. Costco is one company that prides itself on quality products, and has a strict quality control system for what it sells. This has built them a reputation such that customers associate their name with quality.
Service: Money back guarantees, service after the sale, no questions asked refund policies, etc. give the customer confidence that the company believes in and will back the product or service being sold. It removes lingering doubts they may have as it is essentially an insurance policy for the consumer.