Mystery shopping is a term used to describe the assessment of customer service by professional shoppers posing as customers. Some companies have in-house programs, whereby the company hires its own mystery shoppers. Other firms hire "outside" companies like Campus Consulting to provide this service for them.

Mystery shopping is becoming more popular among chain stores because good customer service means higher, steadier sales. Happy customers will return more often and will spend more per shopping visit.

Competition in the retail sector is increasing and becoming more aggressive. Companies are entering the market and providing more selection and better service in order to attract customers. Customer service is now being used to differentiate one retailer from another.

An effective mystery shopping program improves customer service. Store staff and managers will respond to such a program by improving service levels for each customer when they know that a program is in place. Managers can also monitor the company's own standards and policies as set out for the store workers.