I'm sure it's up to both the company and the local/regional manager.
I retired from a "Big Three" cable/internet/voice provider. Our "shops" were analyzed and used anonymously at our Monday Morning coaching sessions. Only the management knew who got shopped, unless it was really really bad and the employee got coached, or if it was a perfect score. Perfect scores earned the employee who helped the customer a lunch out with the store manager, plus a chunk of rewards points which they could use in the company store for everything from work bling to general merchandise, or the ever popular Visa/MC gift card. With a perfect score, the rest of the front end staff enjoyed a pizza lunch and a more modest number of rewards points. It took a clean store, clean parking lot, verbal greetings at the door or from the counter by anybody, plus an overall good experience to earn a perfect score, so it was a group reward.
So yeah, when we either got dinged bad or heard of a nearby store getting rewards, we upped our game and I'm sure it showed.
Funny anecdote... a regional manager was hanging out in the store one morning doing his quarterly observation and a pretty obvious shopper came in and was dealing with a relatively new associate. They were asking all the "buzz questions", which we're coached to recognize and he was practically ready to burst into flames... he so badly wanted to alert the associate she was being shopped. Not a problem, another associated alerted her via the "whiteboard" on the computer and the associate backed up, composed herself, took a big breath and then went into a textbook delivery. Unfortunately, the shopper decided the outside glass door wasn't clean enough and that the associate didn't offer her enough upgrade opportunities and we got a 94 score, or something like that. The regional manager still made sure she got some points.