Secret shopping is when you visit a store and pay attention to details such as store layout, cleanliness, and friendliness of employees. After shopping, you complete a survey about the in-store experience.
In most instances you can purchase anything you want. The products are yours free to keep.
Free to join.
(If you are sent a check with a request to deposit it into their bank account and to wire a portion of the money through a wire transfer company such as Western Union and keep the remainder as a mystery shopping fee, and informed to mail the money immediately as the test is evaluating response time. Don't trust them.)