Don't Fire These 3 Rotten Customers, Profit From Them Deciding not to deal with certain people is like leaving money on the table. How's how to deal with these clients sure to give you a headache.

You know those consultants that go around telling their clients to "fire those customers?" My advice to you is to fire the consultant.

Wouldn't it be nice if all our customers were great? Unfortunately, that's just a fantasy. Business owners like me are always looking for new customers. Few of us can afford the luxury of turning away work. We have bills to pay, people to employ and money to make. If the devil himself pays a premium, well, I'd likely do business with him too (as long as it's not illegal, of course).

I've seen them all, and I've done business with them all. I frequently meet customers who I don't like, trust or want to spend time with. But that doesn't mean I can't make money off them. So instead of "firing" them, I've learned a few ways to profit from them. Here are a few examples, and feel free to substitute "her" for "him," because gender here is irrelevant.

1. The caveman. This is the guy who basically operates out of a craphole. His business has been in the same falling-down shack near the back of an industrial park since he took it over from his dad a million years ago. He's invested nothing into it. His reception area was last re-done when Kennedy was president. So was his receptionist, who barely notices you.

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His employees are huddled in their poorly-lit cubes. His office is disorganized and badly needs a paint job. Is this the sign of a bad customer? Not at all. In fact, he could be a very good businessman. He may be making a fortune. Just look out back and you may see his brand new BMW.

The caveman doesn't care for polish or glitz. He wants your product to make him money. You need to be prepared to show him a tangible, concrete return on investment and to do it in less than 15 minutes. For him, everything's about price. The rest of your relationship will be this way. He will always wonder if he's getting value from what he's spending with you.

2. The complainer. This is the guy who thinks that everyone's out to stick it to him. Being in business for a while kind of wears on you. I get it.

The complainer has probably been running his company for decades and has had to deal with his fair share of swindlers, con men and cheats. He's distrustful of you and your product. He blames others for his problems. He speaks disparagingly of other vendors he works with. He looks like he doesn't believe a word you're saying. He complains about your "high prices" and all the money your company is probably making off him.

Is he a bad customer? He doesn't have to be. To deal with a guy like this you need to grow a thick skin. You'll never earn his trust and you're not his psychiatrist. You'll only be as good as the last thing you do. He will always be a collection issue.

Don't try to make friends and don't consider him to be a long-term customer. Go for short-term profits and charge him as much as you can as soon as you can. Take a deposit up front. Get him to use a credit card. If he walks away then so be it -- let him complain to and then not pay your competitor.

Related: How to Deal With Headache-Inducing Customers

3. The genius in his own mind. The GIHOM is the guy who operates his business out of a second-floor office above a Chinese restaurant in a local strip mall and then freely offers his sage advice for how to better run your company. He doesn't need you, does he? He's got it all figured out. He knows all the answers. He's run successful companies before and conquered the world.

Now he's chosen to run his little mail-order supply company off a busy highway. Just like he chose to get divorced or have no relationship with his kids. Yeah, he's got it figured out alright.

Meanwhile, he treats you like a child. He doesn't reply to your emails for weeks and never apologizes for his lack of communication. He's an incredible success!

To profit from the GIHOM you must never compete with him. Never show him that you know more than him (which you do). Let him be the boss. Take comfort that his behavior is likely due to deep-rooted insecurities or a bad home life. You don't care and you don't want to go there.

Nod, agree with him, be sure to make your recommendations and then sell him what he asks for, regardless of whether he agrees with your recommendations. You will never be right with him. If he's unhappy with your product it will be your fault. If he's happy then it's because of his wise decision to buy from you. Keep your prices high and get everything in writing.

You want customers that appreciate you for what you do, treat you professionally, share the same interests, offer you praises, seek your advice and pay their bills on time. Well, good luck. They are out there, but they're few and far between.

In the meantime, you'll need to deal with customers like the ones above. No matter what "the experts" say, you can't just fire them. But you can profit from them.

Related: When to Fire That, Er, Abusive or Disruptive Customer