Welcome to the latest edition of our brand new weekly series, Break the Rules. Each week our plan is to highlight something you will have heard from some marketing expert as a best practice to be disobeyed at your peril. And we’ll tell you why it’s a rule you should break.

Last week’s rule was Use Social Media.

This week’s rule = Do Anything for the Sale

Your customers are your lifeline. They put money in your bank and food in your mouth. So they’re always right, right?

That’s what many people will tell you. They’ll tell you to bend over backwards for your customers. They’ll tell you to do anything for the sale.

Well I’m telling you today that they are definitively wrong.

Do I think your goal should always be more sales? Of course. I would be a pretty crappy businessperson if I wasn’t interested in growing your business.

But some of the most successful companies are the ones that have found the ability to identify good customers and bad customers. The bad customers are the ones that will cost you more time and more energy for less money. The good customers are the ones that are easier to service, that spend more money, that are happy with what your company provides them.

We all know bad customers. Some of us might even be bad customers of other companies.

Bad customers haggle on price every chance they get. Bad customers spend hours on the phone with your sales reps or customer service teams. Bad customers ask for refunds for no reason. Bad customers threaten negative reviews and BBB complaints to get what they want.

I don’t believe the customer is always right. And I recommend creating a team that is able and willing to identify these potential issues in customers and turning them away. Set firm policies on discounts and refunds. Don’t break them unless you absolutely have to.

Think about the money you save by wasting less time with bad customers, or the money you could make by instead focusing that time on other activities. Stay eager to please your customers, just know that you won’t please them all.

Have a “rule” you think we should write about? Share it with us in the comments below or post it to Twitter @zheller using #marketingrules