I've heard that mystery shopping is where someone, or a couple of people are hired from a private source, or the company where the people are shopping, and they go in to see how the customer service (salesmen/women) treat them through the whole experience. It's a way that businesses see how they're doing on the sales floor, good, bad....and see where they can improve. I know where I used to work would have people doing this so we never knew which customer was the one(s)....so, we had to treat everyone the same. That's how it should be anyway right?....Hope that helped!!