Mystery shopping is a unique way for consumer-minded companies to receive useful feedback on products, services, and other aspects related to shopping from the perspective of an end customer. Companies use mystery shopping efforts to remain in touch with their key shopping demographics, and as a way to evaluate/determine the things that work and those that need improvement.
Through a variety of different avenues, companies can largely achieve the benefits of having mystery shoppers work for them at a negligible cost to their bottom line. That is, compared to the cost of hiring full-time, in-house personnel to perform mystery shopping duties or having other employees spend part of their valuable time carrying out that task.
Most mystery shoppers are targeted by companies as individuals in key demographic areas - for instance, a cosmetics provider might put out classified ads for females aged 18-30 for mystery shopping opportunities in various department stores with a large cosmetics section. Being that mystery shoppers are a unique mix of a type of focus group, and an 'undercover agent' of sorts, there is a certain amount of training involved for creating ideal mystery shoppers.
Depending on the data being observed by companies, mystery shoppers could be trained to focus on identifying ways to improve customer service, examine product quality, or evaluate marketing efforts. Above all else, though, mystery shoppers are valuable because of the 'real consumer' aspect they bring to such an effort, therefore training is generally as easy as a simple conversation detailing the things to notice while shopping.
Unfortunately due to an increasingly large amount of scam organizations using the 'mystery shopper' opportunity as a ploy, many companies are finding it harder to find qualified shoppers without making a significant investment towards displaying legitimacy. Most businesses use temp agencies to staff their mystery shopping needs, unless the project is particularly unique (i.e. shopping for maternity-related items).
In those rare cases where the project requires a specific shopper for the best results, companies generally turn to marketing research firms, private investigators, and even insurance companies who specialize in mystery shopping. This of course drastically increases the upfront price for services rendered, but ensures that a company will get the best quality while avoiding timely and expensive risks.
Today's mystery shopping rates wildly vary depending on how economically-stable a particular market has fared during the economic recession. Generally-speaking, shoppers expect to earn at least $25, and as much as $150 per shop without taking into consideration any extra benefits (i.e. free/reduced-cost meals and/or merchandise, length of assignment, amount of detail in evaluation, various expenses, etc.)