Most major retailers and restaurants use the services of Secret Shoppers. These services are sometimes provided by independent companies and sometimes the individuals that work undercover are actually employed by the corporations themselves.
There are two ways to look at the use of Secret Shoppers. The first is from an employee's point of view. As a retail employee myself, I rather resent the use of these spies. It just feels like many of them are trying to write the most negative possible report in order to make themselves and their job important. Since I am a person that believes in showing respect to all people, especially our customers, I don't understand the need for all these little criteria that we are graded on by the "shopper". We are rated on a scale of one to ten with checklists that include cleanliness of department, did we greet the customer, did we "close the sale" (this is a new corporate tactic to boost sales - resented by employees all around), did we make a parting comment, did we thank by last name? We wear nametags at work, so when we succeed or fail on a "shop", we are recognized. For department managers, a bad report has an impact on their year's end bonus. This all adds up to a Secret Shopper being regarded by retail employees as the villain.
Another way to see the trend toward checking up on your people is from the corporate perspective. Obviously, not every employee is always polite and friendly. Sometimes people are just having a bad day. Retail employees need to learn that their personal lives should not come into play at work. Every customer needs to be treated royally. That is how you get return business. These economically challenging days demand that we do everything we can as a company to keep our customers coming back.
You don't want to be around my boss on the days we get a "bad shop" back. When the department heads come in, their first question is "Did we get a "shop" back?" That way they know whether to avoid the manager for as long as possible or not! See, my boss gets, first, nasty emails, then, nasty visits from his boss. Nobody likes those visits.
So if you sometimes feel that your checker or others you come in contact with at your favorite retail store seem somewhat robotic or even kind of phony, its only because they have a script they are supposed to follow in order to satisfy the spies of the head honchos up there in corporate.