Free samples with a side of serotonin: Welcome to the Costco feeding frenzy

Patio set? "You can’t beat the price." Dyson vacuum on sale? "Suddenly, I need a new vacuum." What’s that in the baked goods? "Who am I to say no to cake?"

Another sure-fire way Costco routinely works its mojo on this 34-year-old advertising executive from Long Island, New York? She loves the free samples, everything from cinnamon raisin cookies to baked cauliflower.

Wait, cauliflower?

"Stay with me here. I walked right past it twice. But I kept watching these people and they're like, 'Oh my gosh, this is amazing.' So finally, I'm like, 'all right, there's something to this,'" said Johnson, who has two refrigerators to house her Costco hauls. "I walked out with two of them."

In fact, she takes home eight out of 10 samples she tries. "Wow," Johnson said, "that's the first time I've admitted that out loud."

No such thing as a free lunch? Don’t tell Costco

People love free food and so does Costco. It makes a fortune from it.

Costco won’t say how much (or anything else on the subject) but no retailer is more famous for its sample smorgasbord.

The savory bites and sweet mini-treats have spawned legions of viral sketches and hot takes. Internet personalities take laps around the aisles to return for seconds and thirds, often in disguise. They forage for clicks by consuming nothing but Costco sample calories for a day or three, hitting every single sample station and by picking vendors' trays clean of soup dumplings and strawberry cheesecake before anyone else can try them.

Then there are people’s odd reactions to an ordinary slice of salami or cup of chocolate milk.

"Whenever I'm presented with a sample of food that I've already had before, and I know I like it, I pretend like I've never had it. I don't know why," standup comedian Josh Sneed recently joked. "I'm just like, what is this? Cheese? Am I saying that right? Cheese? Oh, that's good."

Sneed, 49, doesn’t just get his material from Costco. He gets everything there. He used to drive an hour to a Costco on the other side of Cincinnati until a warehouse opened 10 minutes from his house.

One of the top selling points of Costco? Feasting on the samples, of course.

"This is how gluttonous I am. I'll taste something and like it and I'll know that my son won't. So I'll tell him I think he'll like it just so that he'll take a little bite and then hand the rest to me and I can have a second serving," he said. "I hate that I have a method for Costco samples but, hey, you and I are talking for USA Today so it can't be that bad, right?"

'Free' samples aren't really free

Studies show these tasty handouts thrill shoppers and keep them coming back for more. Free samples are such a staple of the cardholder experience that shoppers grieved when Costco temporarily suspended them during the COVID-19 pandemic.

"There is a real commercial impetus behind samples but they are also part of the appeal of Costco and have a halo effect of showing Costco looks after its customers," Neil Saunders, managing director of GlobalData Retail, told USA Today.

Of course, "free" samples are not really free. They send a subliminal message: Buy me. And often people do.

Saunders says the membership perk is a clever tactic to coax shoppers to try new things and top off their already fully loaded carts with even more Costco loot. The proposition is simple. One nibble in exchange for the purchase of a full-sized product.

"Shoppers who sample something in store are way more likely to buy the product," Saunders said. "It’s basically a marketing activity that boosts revenue."

Why are Costco free samples so hard to resist?

Samples are the highlight of family date night at Costco for Katelyn Melli, 28, and her husband, who, with their 9-month-old son in tow, snack their way through the aisles.

Both personal trainers, the New Jersey couple make a habit of reading the ingredients before buying anything and, as a rule, don’t take home the samples.

"They're all terrible for you, but it's like, they're out, we might as well try them. Just one bite isn't going to hurt us," Melli said.

The last Costco shopping trip was the exception. Melli couldn’t help but snap up a container of organic mango salsa after tasting it on Siete chips.

"It was so good," she said. Is it already gone? Almost, she said. "We went on Monday and today's Wednesday."

The surprise assortment of free samples has become a vital and visceral part of the Costco experience, said Aner Tal, a behavioral economist and visiting professor at the University of Maryland.

That initial taste of a new food can create a lasting first impression – a taste memory – that whets the appetite for that food and other foods like it, Tal said. Free samples also take the guesswork out of a purchase. 

So Costco, through the company Club Demonstration Services that manages the in-store samples, takes great care to engineer an expertly flavorful bite, said Dan Ariely, a professor of psychology and behavioral economics at Duke University.

That single morsel primes people to view the sample as a unique and special treat. While the flavor may not be more intense than any other bite of food, it feels that way because of the intensity of our attention to it in that moment, he said.

And, unlike other bite-sized treats, this one doesn’t cost us anything, making it that much harder to resist. Such is the allure of free stuff, said Ariely.

The other thing about free stuff? It creates a social commitment, an impulse to reciprocate. And Costco shoppers often do so by depositing the bulk version in their carts, Ariely said.

For years, Costco observers David and Susan Schwartz watched samples fly off shelves and into shopping carts, and not just from the sidelines.

While working on their book, "The Joy of Costco: A Treasure Hunt from A to Z," the husband-and-wife team dined on warehouse samples around the globe. In Asia, they sampled vodka and in Sweden, prosciutto carved from a whole leg by a vendor in a pleated chef hat.

"It's clear that the sampling is one of the most popular things that goes on in the warehouse," David said.

Susan says samples got her hooked on Costco croissants. Her grandson, who mainly subsists on a diet of pizza and chicken nuggets, discovered a healthier alternative, madras lentils, thanks to Costco.

Our love-hate relationship with Costco samples

Well, maybe not everybody.

Jesse Fernandez, a 41-year-old comedian and self-proclaimed Costco super fan from San Mateo, California, mostly skips the sample lines, making exceptions only for comfort foods like pizza and macaroni and cheese. But he rarely buys what he tastes.

"The best samples are the things that are the worst for me," he said. So after that one decadent bite, "I just say thank you, Costco, for this little treat. Then I go buy my very boring low-sodium, low-cholesterol, low-anything food."

Free food can also bring out the worst in people. Some belly up to the sample station to graze on pizza rolls and trail mix like it’s an all-you-can-eat buffet. The internet has more than a few names for these freeloaders: locusts, jackals, zombies, trash pandas, even vultures.

"I grab one. Do a loop around the aisle. Grab another one. Do another loop. Repeat until full. Move on to the next sample," one person confessed on Facebook.

The offenders who spark the most outrage are those who park themselves in front of the sample stations, blocking the store’s major arteries and snarling traffic. Some even get physical, shoving fellow shoppers aside or cutting in line to get first dibs. In rare cases, food fights lead to fisticuffs.

The habit that grates on Costco employees? Shoppers who abandon their sticky, half-eaten samples and dirty cups, napkins, toothpicks and wrappers in their carts and maroon the products they sampled but never intended to actually buy on random shelves, leaving warehouse employees to clean up after them.

"Members," one anonymous worker chided shoppers on Reddit, "we are not your maids."