A mystery shopper is a freelance, professional shopper hired by large retail, restaurant, and movie theater chains to check up on their local stores, in order to make sure that customer service is good, stores are clean, etc. Mystery shoppers are also known as secret shoppers, mystery customers, spotters and employee evaluators.

Companies use employee evaluators to help evaluate their products and services so that they can improve customer service. Statistics show that two out of three of the customers who stop doing business with a company do so because of poor customer service. Companies hire and pay these people to evaluate their products or services while posing as customers. In exchange for some form of compensation, mystery shoppers provide a detailed report of their findings, which is useful feedback for these companies.

Many types of companies of all sizes employ mystery shoppers. Restaurants, department stores, grocery stores, hotels, cruise lines and clothing stores hire mystery shoppers. Even gas stations hire mystery shoppers to evaluate the cleanliness of their restrooms. Rather than hiring shoppers directly, companies tend to work with agencies that provide a database of potential employee evaluators.

According to Nation's Restaurant News, 70 percent to 80 percent of fast-food restaurants employ mystery shoppers. McDonald's has employed mystery shoppers since 2002 and 13,600 U.S. locations employ mystery shoppers to make one visit per month, per store. In exchange for a free meal, mystery shoppers take note of the front counter and drive-through, the speed of service, the accuracy of the order, and the cleanliness of the restaurant. They evaluate three menu items (a sandwich, fries and a drink) and the friendliness of the staff. When the shoppers get home, they fill out online reports and e-mail them to the companies.

There are various types of agencies. Reputable agencies will not charge you a fee to include you in their database, although signing up do not guarantee that you will be selected. Your best bet is to sign up with several agencies to increase your chances of getting assignments. Skip the agencies that require you to pay a fee to sign up. Always remeber that if it seems to good to be true then it probably is. The one except to paying a fee is for reach or access to places that will help you locate these agencies. While you can find these places on your own, the time you save might be worth paying for.