Like many consumers, I do a lot of my shopping on Amazon, skimming and sorting through listings by looking for items with lots of user reviews and high average ratings.

But over the past few years, I've grown more cautious as reports have exposed the problem of fake reviews on Amazon and other reviews-based sites. Recent articles by the Wall Street Journal, as well as Consumer Reports, have also exposed potentially dangerous products lacking important safety certifications being sold on Amazon's site.

I reported on fake Amazon reviews myself back in December 2017, while working for New York Magazine, highlighting products such as iPhone headphone adapters that had hundreds of 5-star reviews from users who had never bought the product in question. 

While researching that story, I noticed something odd: Some of the product reviews underneath items were written for entirely different products. At the time, an Amazon spokesperson blamed the problem on a "technical error."

More on Online Shopping

But that strange problem has persisted. I saw it again this July, when I was working on a story for CR on Amazon shopping tips. This time, I spotted an Amazon's Choice iPhone adapter with 4,469 reviews and an average rating of 4.3 out of 5 stars. As I scrolled down, I saw reviews for the adapter, but there were also positive reviews for, among other things, a coffee mug, an add-on for a computer motherboard, and a device for blowing dust out of a computer keyboard. 

I wanted to figure out why this was happening, so I emailed the product listing to a media contact at Amazon. The next day, nearly all the reviews had disappeared, and those that remained were primarily negative. The listing now had just 43 reviews and it was no longer an Amazon's Choice product.

That same day, an Amazon spokesperson got back to me with a statement that said, in part, "Amazon invests significant resources to protect the integrity of reviews in our store because we know customers value the insights and experiences shared by fellow shoppers. Even one inauthentic review is one too many."

But as I looked around, there were more product listings like this—many more.

In one afternoon I spotted more than a dozen listings that all followed the same general pattern: an item, usually sold by a company I'd never heard of before, with lots of positive reviews for products different from the one listed at the top of the page.

I found more headphone adapters—one was an Amazon's Choice product with more than 5,800 reviews, including many for an eyelash growth serum, while others included user reviews for colored gel pens and women's boots. One wireless charger I discovered had reviews for a selfie stick.

The problem wasn't restricted to electronics accessories. An Amazon's Choice posture correction brace had 561 reviews when I found it on August 2, with an average rating of 4.8 out of 5 stars, but nearly all of the reviews were for other items, including dish soap, wooden spoons, garbage bags, dish-washing wands, allergy medicine, and a wooden spanking paddle apparently meant for the bedroom. I saw only a handful of reviews for the brace itself—most of them negative.

I sent several of the product listings I found to my contact at Amazon, and within a few days, they, too, were either stripped of the suspicious reviews or deleted altogether. But other examples I found that I didn't alert Amazon about remained on the site.


Think you've found a product with hijacked reviews? Tweet @Amazon with a screenshot, and use the hashtag #StopReviewHijacking

This curious game of whack-a-mole is a particularly nettlesome problem for Amazon and its network of sellers. It's known in the Amazon seller universe as "review reuse" or "review hijacking," and it happens when unscrupulous sellers find ways to grab positive customer reviews from other products and integrate them into their own listings. It can provide even a shoddy product with thousands of 4- and 5-star reviews. (More on how exactly this happens in a moment.)

Reams of positive reviews can push a product high in Amazon's internal search engine and might trigger an Amazon's Choice badge—this endorsement is given to "highly rated, well-priced products available to ship immediately," the company tells shoppers throughout the site.

Review hijacking is a problem for shoppers as well as ethical sellers, says Chris McCabe, a former seller account investigator at Amazon who now runs a seller consulting firm, ecommerceChris. "Buyers who can't base a buying decision on accurate reviews are harmed because many of them never scroll down to the older reviews that relate to a totally different product." In other words, they can be duped into buying a subpar product. (Here's how to spot products with hijacked reviews.) 

It's unclear if review hijacking is a significant issue on other online retail platforms, but experts I spoke with say the problem is particularly acute on Amazon. The e-commerce giant hosts a wide variety of third-party sellers on its platform, using largely automated tools. At least 2 million companies beyond Amazon itself hawk products on the platform, generating $160 billion in sales in 2018 and making the website a sprawling bazaar in which unethical sellers have an incentive to circumvent Amazon's rules if doing so will place their products in front of shoppers' eyes.

"Just as with Google and other search engines, high rankings are crucial to visibility, and hence sales, on Amazon," says David Spitz, CEO of ChannelAdvisor, an e-commerce technology company. "If you're not in the first few results, you may as well not exist."

Amazon's scale in retail presents it with a problem that bedevils several other big tech companies such as Facebook, Twitter, and YouTube: The larger a company's platform grows, the harder it is to identify and stop bad behavior. "These companies have dedicated trust and safety teams tasked with identifying new kinds of fraud and abuse," says Ben Moskowitz, the director of Consumer Reports' Digital Lab, a major initiative to expand CR's work on privacy and consumer digital rights. "But it's terrifically hard to police platforms that serve millions or even billions of users."

Amazon didn't agree to our request for an on-the-record interview on the topic, but a spokesperson emailed responses to several questions, and sent CR a lengthy statement on the company's efforts to safeguard product reviews. "Any attempt to manipulate customer reviews is strictly prohibited and in the last year alone, we've spent over $400 million to protect customers from reviews abuse, fraud, and other forms of misconduct," the statement reads, in part. "Last year, we prevented more than 13 million attempts to leave an inauthentic review and we took action against more than five million bad actors attempting to manipulate reviews."

But another former Amazon employee I contacted says the company could be doing more. "It's a problem that affects enough customers and violates customer trust often enough that [more] resources need to be put against it," says James Thomson, former business head of Amazon Services, the group that recruits almost all new sellers to the Amazon marketplace. He is now a partner at Buy Box Experts, a consultancy for brands selling on Amazon. "You're being fooled as a customer."

Some Amazon sellers find the problem of review hijacking so overwhelming that they feel the need to fight back themselves. Judah Bergman, who sells toilet training and infant safety products under the brand Jool Baby, routinely fights off review hijackers when they attempt to steal his listings. In fact, he's so frustrated by the practice that he pays for software to spot review hijacking happening on other sellers' product pages, then reports it to Amazon. "I have a template created because I've done it so many times," says Bergman.

(Note: Consumer Reports' website incorporates user reviews, including some imported from manufacturers' websites; we take measures such as moderation by an outside firm to try to ensure that all reviews are genuine. Consumer Reports also participates in Amazon's affiliates program, sometimes earning a commission when consumers go from our website to Amazon.com. Our product ratings are based on lab testing of products we buy at retail, and on our own survey data.)

Misusing Amazon's Own Tools

Experts and sellers we talked to say that review hijacking is executed by slipping through loopholes in Amazon's seller system.

One way shady sellers can abuse the system is to combine reviews from multiple products they've sold over time. A page could sell socks that get great reviews one month, and then the page is revised to start selling headphone adapters the next month. The positive reviews and high average rating will continue to appear—even if the adapters get only a few reviews, all negative. "You're basically hijacking your own product in a sense that you're taking this listing that's got reviews, that's got sales history," says Thomson. "You're just [going to] change out the types of products that are on it." 


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Review hijackers also exploit Amazon's mechanism for letting companies list variations on their product. This system, when used for its intended purpose, allows sellers to list shoes or a sweater in different sizes or colors, with each size having its own page and with the reviews aggregated together.

The system makes sense when used by legitimate sellers. However, review hijackers can use the system to lump together reviews from entirely different products—often from other sellers.

Judah Bergman says review hijackers use a software tool to search for dormant listings that are out of stock, but still have positive reviews attached. "Those are usually the ones that are easiest to just take over without anybody noticing."

From there, hijackers bundle together the product page listings and use a variety of tactics to get the listings uploaded into Amazon's back-end system. "These [products] will be out of stock, but their reviews are all connected together," says Bergman. The only item in stock will be the item that the review hijacker is hoping to sell, boosted with positive reviews from other items.

"What happens is now you've got products that definitely don't follow the variational rules, but if you've got an [Amazon] seller support rep who's not really paying attention, that may be a way you can hijack a listing," says Thomson. McCabe and Thomson both say these problems have persisted for years.

In the case of the posture correction brace I found, the different reviews were labeled as size variations including "Size: later452" (a paper card printing service), "Size: S-5" (dish-washing wands), and "Size: SS-34" (the adult-oriented spanking paddle).

A few days after I forwarded the posture correction brace example to Amazon, the spokesperson emailed a statement that read, in part, "We have clear guidelines about when products should be grouped together and we have guardrails in place to prevent products from being incorrectly grouped, either due to human error or abuse. The detail pages in question have been fixed."

While Amazon acknowledged removing the reviews and product listings I had sent, it declined to discuss in detail how these apparent abuses of the selling system had taken place.

I also wrote to 10 sellers whose products seemed to be benefiting from review hijacking; using Amazon's internal messaging system, I identified myself as a reporter and asked for an explanation.

Most sellers did not respond, and I didn't get much clarity from those who did. HaoXin Store, which had a listing for iPhone headphone dongles that included reviews for iPhone cases and watch-face screen protectors, responded, "Sorry, I don't know what about it! Thanks!" The seller didn't respond to my follow-up inquiry.

Enjoyable Experience was listed as the seller for an Amazon's Choice 5-pack of FEEL2NICE 3-foot iPhone charging cables, on a page overflowing with reviews for other products, including a gaming headset, zip ties, and shaving brushes. This seller did respond, and seemed to indicate that his company had been a victim, not a perpetrator, of review hijacking.

"Dear reporter friend Hello, I am Adam Marks, the head of this FEEL2NICE brand, and I am very grateful for your comments on our products," he wrote. "Our products have been modified by other sellers and changed to sell other products, which led to other products in my product evaluation."

The seller provided an address with QQ, a popular Chinese email service, for follow up questions, but failed to respond to further inquiries.

I found the "FEEL2NICE" brand trademarked by a company called Shenzhen Senmaite Technology Co. Ltd., which is based in China. The company has four additional brands trademarked in the United States selling products on Amazon.

If FEEL2NICE had been the victim of review hijacking, its four sister brands, which also sell iPhone cables, had suffered the same fate. One brand's cables had more than 200 reviews for a hands-free dog leash, while another brand's listing included reviews for a reusable stainless steel straw. After I emailed them to an Amazon representative, the products were either removed or had the majority of their reviews deleted. 

Little-Known Twist on a Persistent Problem

Fraudulent reviews are a well-known pitfall for shoppers on Amazon, and review hijacking accounts for just some of them. Many fake reviews are generated in a clandestine gig economy dedicated to getting people based in the U.S. to buy a product, give it a 5-star review, and then get reimbursed by the seller.

To help consumers fight back against the fake reviews problem, some developers have created tools that attempt to identify when a product's reviews have been manipulated.

Saoud Khalifah runs the review analysis website Fakespot. The site uses a data set of over 4 billion reviews and textual analysis to try to identify suspicious reviews. To use Fakespot, you paste the URL of a product page into a box on the site's homepage, and hit "Analyze Reviews." Depending on how many potentially deceptive reviews Fakespot discovers, the site assigns the item a letter grade from A to F, adjusts the Amazon rating to what Fakespot thinks it should be, and provides an overview of what reviewers said and Fakespot's conclusions.

Although he's adjusted the tool to better identify review hijacking, Khalifah says the phenomenon is particularly tough to spot. "It's harder to trace because the reviews themselves appear to be authentic," Khalifah says. "They're taking reviews that once were authentic or were actually written about the product in question and then just shifting them over. I think a big problem—why this is not being caught by Amazon—is because you need humans to moderate this."

ReviewMeta is another site that tries to help shoppers avoid being duped by fake Amazon reviews. The site might flag a listing where reviews repeat certain phrases more than is typical for an Amazon page; where many reviewers have commented on the same, diverse set of products; or where an abnormally large number of people have reviewed only one product.

Tommy Noonan, the founder of ReviewMeta, says he first became aware of review hijacking in 2018. "People would write and give us feedback on our reports," says Noonan. "And they would say, ‘Hey, your site is screwed up. It's showing reviews from different products, like there's something wrong with your data.'" Noonan says after a bit of digging he realized that this was something different from fake reviews.

"When we first discovered the problem, we wrote about it on our blog and we kind of expected it to be one of those things that the sellers identified this loophole, they started exploiting it, and Amazon is going to do something to fix that within a month," Noonan says. That was over a year ago.

(For its part, Amazon disagrees with the methods and questions the accuracy of Fakespot and ReviewMeta. According to an emailed statement we received from an Amazon spokesperson: "These websites have a business model that is inherently biased towards instilling distrust in reviews on Amazon's and other companies' stores.")

Review hijacking can boost a seller's business much faster than posting fraudulent reviews, says Thomson, the former Amazon Services executive. It takes time to create enough fake reviews to affect Amazon's search results. In contrast, he says, "You hijack in the morning and by the afternoon you're getting lots of sales because you're on page one."

The hijacking problem is widespread enough that on Amazon's Seller Central forums, one seller created a form letter that other sellers can use to notify Amazon if their listing has been hijacked. "We have helped numerous sellers escalate their cases of hijacked or sabotaged listings because otherwise they find action by Amazon teams hard to come by," McCabe says. "Typically sellers say they get no reply at all, or a generic reply saying that the team will look into it."

"Amazon is a company that has solved seemingly impossible problems by tackling them piece by piece by piece," says Thomson. "Why can't they solve this problem?"

How to Avoid Being Tricked

The best way to protect yourself against review hijacking, experts agree, is the simplest one: Don't buy things without reading the reviews, and never rely on just looking at the number of reviews and the average score.

Instead, scroll down through the comments. "My recommendation to all customers is to look at not only good reviews, but also the bad reviews," Thomson says. "How recently were they posted? Do you see reviews for completely different products?"

If you do see misplaced reviews, let Amazon know about it. Underneath every review, there's a link to report abuse—you can fight back against unethical sellers by using it when you see something suspicious.

The same tools Amazon uses to make reviews easier to parse can also make it easier for you to spot review hijacking. First, click the "see all reviews" button and then sort the reviews by the most recent, and note if these reviews seem more negative than the average rating would suggest, which could mean older reviews for a different product are bringing up the average score.

Every Amazon listing page also lets shoppers ask questions about products. If you see questions about trash bags on a page selling a back brace, that's a sign that something is awry. Images uploaded by customers sit at the top of all reviews; pay attention to whether the photos match the product being sold.

Finally, Amazon also collects common phrases from a product's reviews under the heading "Read reviews that mention." If you see the phrase "love these boots" appear under a listing for a battery charger, you might want to move on to a different product.