At times, in the middle of the night, Kim Ju-hyun awakes with a cold dread. He opens the delivery app his restaurant is listed on, Baedal Minjok, to check: Is his star rating still 4.9? Lit by the glow of his smartphone, he scans the line graph that charts the rise and fall of his average monthly rating. He taps through bars showing their distribution. He will check multiple times tomorrow, too.

Even while his rating has survived another day, Kim remains uneasy. For the first few weeks after opening in December last year, he held 4.7 stars out of 5 — a poor result.

“Customers don’t even take notice of 4.7s anymore,” he told Rest of World. “4.6 is unacceptable; 5 seems too fake. The sweet spot is 4.9.” 

In South Korea, where mainstream e-commerce revenue recently overtook offline retail, star ratings have quickly assumed huge authority, business owners and experts say. Within the country’s $19 billion food delivery industry, third in size behind China and the U.S. despite having a fraction of their populations, merchants say that a single subpar review is enough to depress business for days. The dire phrase “star rating terrorism” has entered everyday use. A flood of legislation has been proposed to curb the influence of platforms, including review systems.

“You end up becoming a slave to star ratings,” Kim said

At the heart of it is a model that revolves around attracting users. The top three delivery apps — Baedal Minjok, Coupang Eats, and Yogiyo — are battling it out for market share. Combined, they already hold 97% of the sector, an example of the sort of growing monopoly that has put South Korean regulators on guard. Shop owners have been buckling under the all-powerful metric, beholden to customer needs so that the platforms can pursue growth.

“Tech platforms prioritize the consumer above all else,” said Lee Seong-won, general secretary of the advocacy nonprofit Korean Federation of Self-employment and Microenterprise. The ratings system, he added, is a symbol of their “ultimate authority.” 

In recent years, as livelihoods become increasingly dependent on tech platforms, online ratings have grown fraught. In the 2010s, Uber drivers rose up against the harsh metric of the star rating, which often saw them penalized by anything less than five stars. (One of Uber’s solutions was to implement two-way ratings.)

In China, according to one researcher who spent six months working at e-commerce giant Alibaba, sellers engaged in “review brushing” — the practice of boosting one’s own score while sabotaging those of competitors. Instacart shoppers in the United States have protested their vulnerability to unfair feedback, while companies like Lyft have drawn criticism for encouraging consumers to rate as highly as possible, rather than honestly. 

Kim’s restaurant, a small kitchen lined with shiny stainless steel countertops, is delivery-only. He hands steaming containers of dakbal — Korean spicy chicken feet, Kim’s specialty — through a sliding window to delivery drivers, the establishment’s only visitors. 

For new places like his, which lack enough reviews to hold up a stable average, even a single one-star review can be ruinous. Kim’s strategy has been to limit himself to a strict five orders a day, amounting to about 150,000 won ($125) in daily sales.

“I’m anxious from the moment the food is sent off for delivery to the moment the rating comes up,” he said.

In an emailed statement to Rest of World, Baedal Minjok spokesperson Kim Oh-new pointed out that the review system “broadens consumer choice,” and provides “a communication channel between merchant and customer.”

Even so, the pressure exerted on merchants like Kim has given rise to the expression “star rating terrorism” — a term for bad-faith consumer activism that uses star ratings to intimidate, extort, or unfairly punish merchants, knowing they must go the extra mile to protect their ratings. 

In May 2021, a snack shop owner in her 50s collapsed from a brain hemorrhage while discussing a customer complaint with Coupang Eats. The customer had demanded a full refund, saying that a single fried shrimp had become discolored after a day in the refrigerator. They lodged a complaint within the app, leaving a scathing one-star review. 

Coupang Eats followed up with multiple calls to the owner and, in transcript fragments published by South Korean media, appeared, above all, to be concerned with placating the customer. The owner, unnamed in the reports, collapsed during one of these calls. As she was shuttled to the hospital, unconscious, Coupang Eats again rang the restaurant, instructing the shop employee who picked up the phone: “Please tell the owner to make sure this same problem doesn’t happen again.” 

The owner died on May 29 after three weeks in the hospital, and the incident has since become an emblem of the power imbalances in the platform economy. Merchants, some critics note, have come to be treated like subcontractors, answerable to both consumer and platform but with few protections against abuse. 

“We’re in a system where, if the consumer demands something, we have no means of pushing back,” said the husband of the deceased owner, in an interview with South Korean media. 

Merchants’ rights activists blamed Coupang Eats’ system, which, they said, “gives star ratings and reviews an absolute authority.” In June of last year, Coupang Eats apologized for failing to provide adequate support to the merchant and announced measures to better protect those listed on its app, including an update that would allow merchants to reply to consumer reviews. 

Coupang Eats did not respond to multiple requests for comment for this article.

Open any of South Korea’s delivery apps, and it is obvious why Kim, the dakbal shop owner, is worried: it’s difficult to find a restaurant rated below 4.5. The tendency for online ratings to skew positive is common; a 2021 study in the scientific journal Nature observed the same phenomenon in the U.S.

This kind of rampant grade inflation fuels a relentless cycle of ratings competition. Many restaurants hold “review events” where they promise a small freebie — an extra side, a soft drink — with the expectation of a five-star rating and a glowing written review in return. Occasionally, these freebies might arrive humorously labeled with a sticker that says “review bribe.” Both parties know the deal. 

A Consumers Union of Korea survey last year found that these events did motivate reviewers: among the respondents, 53.6% said they were nudged to “review as positively as possible,” while 12.5% said they leave unconditionally positive reviews.

Kevin Nam, who runs an independent burger shop in Seoul, has managed to hold a 4.9 for the last few months, but frets about the inevitable fall. A few months ago, when he received a three-star rating, Nam saw his usual $400–$500 in daily sales collapse to around $170 for a few days, until he could regain his rating. “It’s incredibly nerve-wracking,” he said. “You become very conscious that you’re falling behind competitors.”

(After Nam started including a bottle of Perrier with every order, he saw his number of reviews skyrocket over the course of a month, from three or four to more than 40.) 

Other restaurateurs might appeal to the emotions, with heartfelt handwritten notes decked out with emojis and profuse thanks — an act now common enough that mass-produced versions can be bulk purchased online

The pressure has also encouraged merchants to use gray-market review counterfeiters who advertise their services online. All three of South Korea’s main delivery apps now use automated monitoring systems to filter out fraudulent reviews, while Baedal Minjok has been tracking down and taking ratings counterfeiters to court. In May 2021, one of the app’s targets — a counterfeiter who had made over 100 million won ($82,000) over a period of 31 months — was sentenced to 10 months in prison for “obstruction of business.” The counterfeiter had produced 35,000 fraudulent reviews, according to media reports.

Occasionally, these freebies might arrive humorously labeled with a sticker that says “review bribe.” Both parties know the deal.

In the wake of the snack shop owner’s death, advocacy groups and legislators have proposed a flood of bills and amendments, including measures to hold platforms accountable for the dissemination of information — namely, consumer reviews that cause harm to the merchant.

“After the death of the Coupang Eats merchant, the biggest question on my mind was: what can we do about it legally?” said Lee Seong-won of the KSFM.

Among other campaigns, Lee’s group has been working with South Korea’s Fair Trade Commission and legislators on drafting the “Online Platform Fairness Act,” first proposed in January 2021. The bill’s key provisions include rules against platforms abusing their superior bargaining position to impose unfair obligations on merchants, as well as those making them explain any search or visibility algorithms.

But it has faced strong opposition from the Korea Internet Corporations Association, the country’s foremost tech lobby, which has objected to the bill on grounds that it would stifle innovation. It has been whittled down since the earliest draft — a “shell of the original,” admitted Lee — and passage remains uncertain. But even in its most basic form, he said, the legislation would mark an important turn. “The main goal was to establish it as the first law on online platforms, and to add to it down the line.”

Ratings have become a “game” for consumers,” he says, and he would rather see them abolished in favor of something that encourages slower and more thoughtful engagement, like text-based reviews. “Of course, this system will also require some moderation,” he said, “but it would encourage consumers to put in the effort.”

Naver, South Korea’s largest homegrown internet portal and search engine, has begun phasing out star reviews, based on concerns about their negative impact on merchants. Announcing the move in March 2021, Naver CEO Han Seong-sook said: “In the past, the reviewing environment has been a one-sided space based on star ratings. … In the future, Naver will redefine it into a space that better highlights the merits of stores.”

A July survey indicated that users were largely satisfied with the new system — a text-based one that prompts users to select preset tags describing their experience. But users still voice concerns that it has taken away their ability to punish bad apples, such as restaurants with poor hygiene. 

Honest reviews, said Kim Ju-hyun, the dakbal shop owner, are ultimately what merchants want. Since opening December, Kim has spent countless hours honing every aspect of his product, from visual presentation to his house-made salad dressing, painstakingly developed with the help of a culinary consultant.

Even so, Kim finds that it’s impossible to outrun the realities of the ratings game. Despite vowing not to run review events, he has begun adding a free side of vegetable twigim, or tempura, for a limited time. “Delivery apps represent such a large portion of my restaurant’s marketing footprint that it’s impossible not to keep thinking of consumer perks that might help my rating.” 

In one review posted to his Baedal Minjok page, a customer thanks Kim for the free side and gushes over the salad dressing — “a stroke of genius.” Included in the collage of photos is one of Kim’s heartfelt thank-you notes, written on a pink slip of paper in a messy blue scrawl. Displayed at the top of the post is the final judgment: five stars.