Earlier this month, Savannah Hill, who just started as a recruiter at the company, posted photos to LinkedIn of the gift box Calendly sent her along with her offer letter.

“Congratulations,” the letter reads. “You just got a job offer from Calendly!” The box included a T-shirt with the company logo, cocktail mix, a thermos, a glass candy jar, a sheet of stickers, and a card outlining Calendly’s values.

The welcome gift bag is a hallmark of the company’s hiring process, Kelly Minella, Calendly’s head of recruiting, tells Fortune. 

“Experience is so important to us; the swag bag gives a glimpse into what the employee experience will look like at Calendly,” she says. “We want anyone who enters our application process to leave as a Calendly ambassador.”

Calendly started sending the swag bag alongside offer letters well before the pandemic sent many employees across the U.S. to work from home and forced HR to figure out a new way to onboard. The practice first started in 2018, as a way of extending gratitude to candidates, and showing them the company recognized the time and energy it takes to apply and go through the interview process.

Minella also thinks the swag is important if the candidate is entertaining multiple offers—it helps Calendly to stand out from the rest.

“We’re a company that’s innovative, not just from a product standpoint, but an experience standpoint,” Minella says. “We want to do what it takes to make sure we’re on top of the latest and greatest. With the boxes, we just hope it shows applicants that we start with human. And we want to say thank you for giving us a chance to get to know you better.”

The efficacy of the swag bag

“Swag bags sound like a cool concept, but I don’t know if they make sense for every type of business,” Mary Elizabeth Elkordy, founder of PR firm Elkordy Global Strategies, tells Fortune. “Candidates really care about the intangibles, like July Fourth and Christmas week off; those are more important than gifts.”

At her company, Elkordy will occasionally send gifts for special occasions—birthdays, weddings, Employee Appreciation Day, which is next month—but has spent much more time fine-tuning the benefits package. 

“A swag bag is cool, but people really care about their salary and job potential,” she says, adding that she prioritizes things like paying half of health, dental, and vision costs, and matching a 401(k).

Elkordy insists that any gift a company sends an employee must be given authentically, without any expectation of a thank-you. 

But swag bags aren’t just to show appreciation—they have a clear purpose, argues Peter Clare, president at Jobvite, a talent acquisition software company.

“What’s driving swag bags is the increasingly high rate of candidates ghosting companies,” Clare tells Fortune. “Hiring is taking longer than ever, and you probably have to go above budget for the hire. Some candidates will accept the offer, go through the notice period, and then won’t show up on day one.”

By sending an offer letter with an accompanying swag bag, employers want to dissuade someone from ghosting, which they would only do if they feel alienated, Clare says.

“Employers move to create a tighter connection with candidates through the whole process,” he says. “Swag bags are anti-ghosting tactics, and post-offer, they may get a swag bag during onboarding. Same idea: to try and keep new employees as engaged as possible.”

Boardrooms are facing a great reckoning with executives worried about too few candidates applying for jobs and even fewer accepted offers. One of Jobvite’s clients, a fast food chain, is debating the idea of sending all applicants a $5 gift certificate in an effort to maintain a positive association with the brand, even if their application is rejected. 

“At this stage, any employer that’s not personalizing the applicant experience is going to fall behind,” Clare says. “Even things like texting with applicants. You’ll get 10 times the engagement from candidates you’re texting versus those you’re emailing.”

The average cost of replacing an employee is $4,000, Clare says, which makes these kinds of small decisions crucial. What’s more, that $4,000 figure is just the physical recruiting cost; there’s also the productivity loss to consider.

“The best thing employers are doing to retain their talent and attract new talent is driving up authenticity and focusing on the experience,” Clare says.