Courtesy of Sheldon Yellen

Sheldon Yellen, CEO of the property-restoration company BELFOR Holdings, Inc., handwrites holiday cards to each of his 9,200 employees as a way to say thank you.

He travels with a suitcase full of stationery. He also pens handwritten notes for thank-yous, anniversaries, and birthdays.

Researchers and career experts say the most successful corporate managers are those who can thank their employees and give them words of encouragement.

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If you happen to sit next to Sheldon Yellen on your next flight, chances are he'll be writing birthday cards - lots and lots of them.

Yellen is the CEO of BELFOR Holdings, Inc., a disaster-relief and property-restoration company. And since 1985, long before Yellen was chief executive, he has written a holiday and birthday card to every employee of the company every single year.

Today, as CEO, he handwrites 9,200 cards annually - one for every employee.

"There is an inside joke with acquisitions that I ask prior to closing: 'How many more people?'" he told Business Insider's Chris Weller in 2017 - meaning, How many more birthday cards do I have to write? - "since I am constantly calculating that in my mind rather than 'What is the EBITDA [earnings before interest, tax, depreciation, and amortization]?'"

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Yellen began the practice in 1985. He started doing it after he was hired by his brother-in-law, since many of the current employees felt he was being given special treatment. If nothing else, the cards would encourage people to stop by his desk to say thank you, he thought.

"And it worked," he said. "It got people talking, we started to communicate more, and I like to think it helped me earn respect within the company."

The importance of workplace gratitude

Fast forward to today, and Yellen is now bringing suitcases full of stationery with him on every plane trip he takes.

But the practice isn't just for the thank you - Yellen writes thank-you notes, anniversary cards, holiday cards, and writes to his employees' kids when they are sick, company director of marketing communications Alexandra Gort told Business Insider this year.

Yellen has found taking the time to write out a card for each and every person has created a culture of compassion throughout the company.

"It's also something that doesn't have to cost a thing," he said. "When I learn of random acts of kindness being performed in the field, I take it upon myself to again, reach out in writing, and send a thank you card so that person can know they are appreciated and that their efforts don't go unnoticed."

Yellen has a point: career experts say the best managers are ones who dole out positive reinforcement to hard workers. Workers told Business Insider that the traits they admire in their bosses are when they can call attention to career accomplishments, and expresses genuine interest in their well-being.

Research indicates good employees will quit their jobs if they aren't recognized enough for their efforts.

Yellen, for one, said his gesture made for a more compassionate, gracious workplace. Some managers have even taken up the habit themselves of writing cards for their team members, clients, and loved ones.

Other CEOs may consider the gesture frivolous or a waste of time, but Yellen is quick to disagree. He said his experience has taught him that the value keeps coming back in spades.

"When leaders forget about the human element, they're holding back their companies and limiting the success of others," he said. "Focusing only on profit and forgetting that a company's most important asset is its people will ultimately stifle a company's growth."

Chris Weller contributed to a previous version of this article.

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