If you've been in business long enough, you've probably had the displeasure of dealing with customers who force you to do all the heavy lifting on a deal, use you as a bargaining chip while negotiating with one of your competitors or simply act unprofessionally when they hit even the slightest snag.

Inc. magazine has a quick and useful column by Geoffrey James that names each of these customers by type and gives you the advice you've probably been eagerly waiting to hear: Drop them.

James is direct and doesn't mince words. Check out the title of his latest book. Having experienced each of the offending customer-types first-hand, James has concluded that IT businesses shouldn't maintain toxic customer relationships. They're simply not worth the trouble.

That's a tough argument to make, but it's true. The revenue a problem customer represents may not be worth the time, energy and resources required to put it in the books, especially in the fast-paced and ultra-competitive environment solution providers inhabit today.

Check out James' column here. Does this describe any of your customers? Do you have the horsepower to let them go?