"Service Tri-tone" refers to a sentence in which a merchant or waiter expresses his thanks and tells him whether it is necessary to continue the service after the customer consumes. Usually, this service method is applied to catering, hotels, shopping and other service industries, which can effectively enhance the customer experience.

Serving Sanyin is an important part of the century-old cultural heritage "Nanjing Jinling Drumming". The waiter knocked on the mother drum, plain drum and male drum on three sides, and shouted the slogan of "three services" while beating the drum, indicating that he had arrived at the door and was ready to serve the guests.

Service Tritone is also widely used in the express delivery industry. The waiter delivered the parcel to the customer, quickly rang the doorbell and shouted "three times of service" to remind the customer that the express delivery had arrived. This method is simple, fast and effective, which can improve customer satisfaction and service quality of express delivery company.