For merchants, the biggest advantage of this method of spending money on defects is that it can find and improve existing problems in time, so as to get rid of the disease. In my opinion, being a "mystery shopper" is a very happy thing. You see, shopping, eating, tasting wine in bars, traveling and playing golf are all paid "jobs", which is undoubtedly a shortcut to gold mining.
It should be noted that the requirements for the quality of employees are relatively high.