Huffington said the tradition began as a way to make her burgeoning media company feel like a family. And she made sure the ritual would survive, even when the Huffington Post was sold to AOL in 2011. “I didn’t want to be told that we couldn’t justify the expense,” Huffington said. “So it was actually part of the sale discussion, believe it or not.”

Over the years, sweater day became a company-wide event. And those who didn’t like the color or style in their box had the chance to swap with a neighbor. Because each year was associated with a distinctive style—2011, for example, included shawl-neck styles care of J. Crew and v-necks from White & Warren—employees could also measure their tenure at the company by their wardrobe.

“It was funny—we had people saying, ‘I’m a five-sweater’ person,” Huffington noted. “It was a way for people to mark how long they’d been there.”

I myself am a two-sweater person. One a lightweight, light-blue v-neck and the other an oversized, navy wool pullover (which I swapped with a male coworker) with a chunky knit pattern. Even though I no longer work at the media behemoth, I break out these sweaters every holiday season as a reminder of the often-stressful but always interesting time I spent working as a HuffPost Trends Editor.

Jodi RR Smith is president and owner of Mannersmith, a company that specializes in corporate etiquette. Not surprisingly, Smith said she gets a lot of questions this time of year about how and when to give presents in the workplace.

“The gift has to fit within the company’s professional structure,” Smith says. “So the ideal gift is something that fits within the culture, is appreciated by the majority of the employees and makes sense professionally.” In other words, a beautiful pen might not make much sense for members of an IT department, although it would be a thoughtful present for nurses and doctors who take handwritten notes all day.

While every office has different needs, Smith says she thinks Huffington’s sweater tradition was successful for a number of reasons. For one thing, Smith says the sweater festivities turned the concept of company loyalty into something fun. Both newcomers and veterans received visual confirmation every December that staying with the organization was valued by management.

At the same time, the one-size fits all approach (figuratively if not literally) achieved consistency without being dry or boring. No matter where you are in the corporate hierarchy, Smith explains, the practice proved everyone was part of the same team.

From an employer standpoint, this is a huge win. An abundance of research shows companies with low employee loyalty are likely to suffer from a loss of expertise and productivity. As Emma Seppala and Kim Cameron note in the Harvard Business Review, one of the best ways to maintain loyalty and increase engagement is by fostering a positive work culture.

The Huffington Post has received mixed reviews from its employees over the years, including high-profile pieces like this 2015 piece on Gawker. And yet, it has managed to retain a core of incredibly loyal writers and editors and in fact, I’ve known several HuffPosters who left only to return soon thereafter. (No word on whether they were lured back with free sleepwear.)

As someone who has spent plenty of time in the high-pressure world of media startups, I can attest to the power of camaraderie. Nap pods are nice and everybody loves a good cereal bar, but free snacks can only get you so far. Ultimately, the Huffington Post may not have always given me the warm and fuzzies, but Arianna’s sweaters have never let me down.

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