Did you know that pumpernickel bread is thicker in the middle and smaller at the ends?

One deli apparently didn’t. Because once they made me a sandwich from the end of the loaf, which was about half the size of my normal sandwich. And when I took it back to the counter and told them so, they said, “too bad.” I then gave a response that every business should fear hearing:

I politely said “thank you” and left.

Had I actually gotten upset with them, they might have called a manager. Or perhaps reconsidered and made things right. At the very least, they would have had a data point about their service. Instead, I quietly declared the game over. And went from eating there three times a week to staying away for over a year. Doing the math, they probably lost several hundred dollars of profit on that one sandwich. All because I am a nice customer who wouldn’t dream of causing a scene.

Now, in all likelihood, your business doesn’t make sandwiches. You write copy, you do strategic planning, you sell things online, or whatever. But the same principle applies: the nice customer is one of the greatest risks to your profitability.

The obvious problem with nice customers is that they say nothing and wander off, like I did. But there are other risks that cut even deeper:

They influence your business model. Suppose your policies or your service are truly miserable. If 95 percent of your customers say nothing, while silently thinking you are a pain in the ass, you are at great risk of perpetuating the status quo because “most people never complain.” (Oh, and by the way, according to a White House consumer affairs study, over 95 percent of dissatisfied customers never complain. Roughly 90 percent of them never come back.)

They tell others. People who won’t tell you what went wrong still talk to people. And in an era of social media, this effect can be magnified tremendously. Want proof? Go to Amazon.com and look up toilet plungers. See the dozens and dozens of customer reviews? If people take time nowadays to share how they feel about their toilet plunger, don’t presume that you will escape having people talk about you.

You silently brand yourself. At the end of the day, we are all a 15-second soundbite. Have you ever noticed how almost everyone has the same opinion about other businesses, or doctors, or whatever? “She’s really competent.” “He’s crabby.” “They are never on time.” Meanwhile the subjects themselves are clueless about their “brand” with the public, because people are too nice to tell them.

How can you protect yourself from the damaging effects of nice customers? First, listen better. Do proactive surveys, or better yet anonymous ones, to see what people really think of you. Respond better when people do complain, and think about how these people might reflect everyone else’s experiences. Take a fresh look at your business through your customers’ eyes, and benchmark what it is like to do business with you versus others.

Best of all, calculate what I call your CPC value – the cost of pissing off the customer. In the case of this deli, their CPC was pretty expensive relative to the sandwich. Then manage your business so that you have as little CPC as possible. That way, you stand a much better chance of having your “nice” customers truly be a nice thing for your bottom line.

So what do you think? Are there some things in your business that you need to change? Please share in the comments below.