Tuesday afternoon at 12:30 p.m. Petra B. enters the store. She is on a mission. Petra B. is a mystery shopper. Armed with her wallet, a trained eye and exact instructions by the storeowner, it is now up to her to put the service quality of the store under the microscope. Mystery shoppers are the kind of customer, salespeople should be especially polite to. However, as the term ”mystery shopping“ already implies, service personnel is not able to distinguish them from regular shoppers. And there is a good reason for that.