People never respond well to criticism of their actions.

There are some people with the patience of saints who will hear you out if you start telling them what they're doing wrong. They might even listen to you. But in response to nothing but criticism, they'll probably end up not liking you, even secretly.

Why on earth, then, is it standard practice for people to call and complain to a manager when they have a bad experience with an employee? Is this going to improve things?

I have a "bad" customer service experience almost daily. Some interaction with a human being, either by phone or in person. My strategy in these situations is the same 96% of the time: completely ignore them.

You might have a bottle of water with some mud at the bottom. Provided you don't stir up the contents of the bottle, you can drink the water without getting any dirt in your mouth.

The posture in these situations should not be to find the bad and try to stamp it out by mentioning it. When we experience good customer service, we take it for granted and accept it as expected, but I think when someone exceeds or even meets our expectations with a kind attitude, that's when we ought to be demanding to talk to the manager.

"This employee was extremely helpful and brightened my day. Thanks."

(It just might have the power to create good vibes, on an otherwise unlucky Friday the 13th.)