One of the misconceptions about mystery shopping is that it should be a secret. It should be anything but. Your employees should be able to articulate every detail of the mystery shopping observation.
About five years ago, we started referring to mystery shops as service evaluations. The reasoning was simple, you are not evaluating a mystery or a shopper. The service evaluator is measuring the execution of a sales process, as it relates to increasing customer satisfaction and, ultimately, customer loyalty.
The only aspect of mystery shopping, secret shopping, service evaluations, or whatever you choose to call it is the scheduling. If you let employees know that you have one shop a week, they can count. They will revert to the behavior you want to avoid after they see the one report is completed until the next one is due.
