Mystery shoppers
(a.k.a. “secret shoppersâ€) pose as customers in order to evaluate the quality of customer service they receive. They will perform specific tasks such as purchasing a product or posing a specific scenario, and then providing critical insights needed for an organization/brand to drive effective change within their business.
http://www.bestmark.com/become_a_shopper.htm?r=IL18986 (http://www.bestmark.com/become_a_shopper.htm?r=IL18986)