As a leader, you have many important responsibilities, but one of the most important is also one of simplest. Unfortunately, it's also one that is often forgotten: thanking your employees for a job well done. Skip this simple step and you run the risk of losing your best people.

There's a company that's been a customer of mine for about five years, and that accounts for a meaningful portion of my revenues. For most of that time, they were both easy and pleasant to work with, and they made their appreciation of my work clear. Not with extra compensation or bonuses (they were paying me fairly to begin with) but by simply letting me know on a regular basis that they appreciated and valued my work.

Then they changed direction and hired a new manager, who became my contact with this client. The new manager was tasked with making several changes. His plans for how to do this meant some big changes to the work I was doing. He also asked me to redo a lot of work I had completed under the previous regime. In the name of good client relations, I agreed. 

He never thanked me for any of this. Instead, over the following months, he often asked me to redo work, or sometimes rejected it. I figured that when the current year's contract was finished, the customer would not want to renew it, since this manager had never thanked me for anything or said that he appreciated my work. Recently, he did get in touch to say that something I'd done had helped to boost sales. Even this information did not come with the words "thank you."

A few days after that, I got word that the company wanted to renew our contract. Saying no was one of the easiest decisions I've ever made, even if it will cost tens of thousands of dollars. Not that I can fault the new manager exactly--it's not in his job description to thank me or make me feel wanted. But I've learned over the years that working for clients I don't enjoy is a mood-killer that affects my productivity. And there are plenty of other opportunities I'm now free to pursue with customers who do say thank you when it's appropriate.

It's not just me. If you have smart, creative, hardworking employees in your company, or contractors in your stable, you can bet they have plenty of other offers to work for someone else. Not only that, in a recent survey, 81 percent of respondents said they would work harder for a grateful boss.

So if you aren't thanking them frequently--why aren't you? I know it's human nature to focus on the negative when managing people who work for you. I've been guilty of doing that myself (until one helpful contractor pointed it out to me). The fact is, if you don't remember to give the people you work with not just compensation but regular expressions of gratitude, you're liable to lose them. Thanksgiving and the year-end holidays are the perfect occasions. If you haven't been thanking employees enough (or at all), there's never been a better time to start.