Mystery shopping (or mystery customer) is a management tool used to find out how customers are being treated. Retail companies use it to get an idea about how their branches are being managed and operated. Also franchise chains use it to make sure franchisees are keeping to the agreements made with the parent company.
The idea is to get information which is otherwise hard to obtain. Quality of service, or compliance with regulations and/or agreements are what is often investigated. A company hires a person to be a customer. The company being evaluated does not know who the mystery shopper is.
Mystery shoppers perform specific tasks such as buying a product, asking questions, registering complaints or behaving in a certain way. Afterwards, they provide detailed reports or feedback about their experiences.