As a requirement put forward by customers, the quality of after-sales service provided by manufacturers or businesses will be in direct proportion to customer satisfaction. The after-sales service is well done. If the customer's requirements can be met, the customer's satisfaction will naturally continue to improve; On the contrary, if the after-sales service is not well done or not done, customer satisfaction will be reduced, or even extreme dissatisfaction will occur.

After customers are satisfied, they usually continue to buy products they are satisfied with, and carry out positive communication through word-of-mouth publicity, which plays a strong and powerful role in improving the market share of products and brand reputation. If the customer is dissatisfied with the service, the empirical research results show that 96% of the consumers will not complain about the poor service, but 90% of the dissatisfied consumers will not buy the company's products and services, or tell at least 9 other people about their experience, and 13% of the consumers who have had dissatisfied experience will tell more than 20 people about their experience.