Unscrupulous businesses are exploiting weaknesses in Amazon’s review system to fraudulently boost their listings with reviews lifted from completely different products, a Which? investigation has found.
The consumer champion found that nine out of 10 of the top-rated headphones on the online marketplace carried glowing reviews for unrelated products, ranging from cuddly toys to jigsaw puzzles and umbrellas.
Which? believes that these listings have been misleadingly boosted using a ‘black hat’ marketing tactic – where a seller exploits loopholes to get an unfair advantage – known as review merging abuse. It suggests that Amazon is struggling to prevent third-party sellers from manipulating its review system to boost their products, which risks undermining shopper trust. The Competition & Markets Authority says £23 billion of consumer spending is influenced by online reviews.
Which? looked at bluetooth headphones – a popular category on Amazon’s UK website – and arranged the results by ‘average customer reviews’, to mimic how a consumer might shop if they are looking for the best-rated headphones on the site.
There was just one established brand across the top 10 headphones – Bose, which came eighth and did not show any signs of review abuse.
The other nine were unknown or little-known brands, which did not appear to be sold on any other sites apart from Amazon. Which? found they had been artificially boosted by thousands of irrelevant reviews for entirely different products – including umbrellas, personalised jigsaw puzzles, bowls, glass jars, extension leads, cuddly toys and a keyboard desk tidy. In some cases, the listings had no reviews for bluetooth headphones at all.
Two of the nine artificially boosted listings Which? found had earned the coveted Amazon’s Choice badge, despite being inflated by clearly illegitimate reviews.
Merging reviews can be a legitimate way for sellers to manage their catalogue when they have a close variation of an existing product to add to a listing – such as the same product available in a different colour. But doing this for unrelated products is against Amazon’s terms and conditions. It is misleading, and makes a product appear more popular than it is – and more appealing to consumers looking to make a quick purchase.
While sellers can merge their own product reviews, some unscrupulous sellers find ways to merge reviews from other people’s listings too, which is known as ‘hijacking.’ On Amazon’s own forum for sellers, there are more than 50 threads mentioning “review hijacking” as the topic, where people complain of having their product reviews “co-opted” and “stolen” by other sellers.
The most highly rated headphones, boasting five stars out of five, were ‘Amazon’s Choice’ and had received 40 reviews – but none of the reviews were about headphones. All of the reviews, including three reviews clearly showing photos of the product, were for “plushie” toys – a “cute” and “adorable” cuddly stuffed animal apparently loved by children and adults alike.
The second pair of headphones to be labelled Amazon’s Choice were entirely propped up by reviews for an extension lead several shoppers claimed could be a fire hazard. Which? found no mentions of headphones or earbuds in any of the 207 reviews, while all nine photo reviews showed an extension cable. Most of the reviews for the product were five stars, and beneficial to the rating of the headphones, but several reviewers claimed the extension lead was unsafe.
One listing had 863 reviews for a personalised jigsaw puzzle – with just three reviews for the headphones themselves. Another had 1,386 reviews that appeared to be for beach umbrellas – including 64 photo reviews. Which? did not find one review for this listing that mentioned earbuds or headphones.
Which? focused its investigation on just one popular product category, but has also seen the issue across other categories, including smartphone chargers with reviews for surge protectors, tweezers boosted by reviews for non-stick kitchen foil, and blackhead removing nose strips boosted by reviews for wigs.
Ecommerce experts told Which? that sellers do this by either merging their own unrelated listings or hijacking dormant ‘zombie’ listings owned by other sellers, and re-topping them with their own product name. They said it is relatively easy to do and, in their view, there are not enough safeguards in place to stop it from happening. While it can sometimes happen in error, deliberate and illegitimate review merging is designed to game the system.
Amazon told Which? that it is disappointed when bad actors evade its systems, and emphasised that it does have proactive measures in place to “detect and block the vast majority of abuse in our store automatically” and continues to invest in its tools and processes. It previously told Which? that consumers should report fake reviews by using its ‘Report Abuse’ function. Which? tested this function on the website by manually reporting the first page of incorrect reviews on the page of each of the nine bluetooth headphones.
After four weeks, three of the listings Which? reported for abuse still had clear signs of review merging and were still available for sale. These included the headphones with reviews for a keyboard desk tidy, the headphones displaying reviews for personalised jigsaw puzzles and the headphones boosted by reviews for an extension lead several people claimed was unsafe. These headphones, with reviews for an extension lead, were marked Amazon’s Choice after Which? had reported the reviews abuse.
There appeared to be some action taken on the other listings. One listing was deleted entirely. Two listings remained but with all the reviews deleted. The other three were marked ‘unavailable’ – but still displayed all the reviews Which? had reported.
Which? believes Amazon needs to better enforce its own policies, particularly given the consumer champion first raised concerns about review merging back in 2019. The online marketplace must ensure that mechanisms put in place for sellers do not end up having negative consequences for shoppers using the platform.
Further action is needed to address the ongoing problems caused by misleading reviews on Amazon and other online marketplaces. The CMA’s fake reviews investigation must get to the bottom of the issue and ensure that major shopping sites are protecting consumers from these unfair practices.
However, the CMA’s work alone is not enough. The government plans to tackle fake reviews as part of its consumer and competition reforms and should bring forward new laws to banish these exploitative practices as soon as possible.
Rocio Concha, Which? Director of Policy and Advocacy, said:
“Unscrupulous businesses are exploiting weaknesses with Amazon’s review system, leaving shoppers at risk of buying products boosted by thousands of bogus five-star reviews.
“Once again, this reinforces the importance of the CMA’s ongoing fake reviews investigation getting to the bottom of the issue and ensuring that major shopping sites are protecting people from these unfair practices.
“The government also announced its intention to tackle fake reviews as part of its consumer and competition reforms and should bring forward new laws, in the upcoming Queen’s Speech, to banish these exploitative practices as soon as possible.”
Alistair Soames, a 50-year-old investment manager from Surrey, saw evidence of review merging when he was shopping for earbuds on Amazon in 2019. After some digging, he noticed some of the products were boosted by reviews for shower curtains and kitchen knives.
“I read the reviews [for some of the headphones] and many were absolute nonsense. They were for shower curtains and kitchen knives. It was the pictures that gave it away – I saw a shower curtain and thought: hang on a second, what has that got to do with headphones?”
He complained to Amazon, and sent several other emails highlighting the issue on other products, he says, but is “disappointed” in the response.
At one point, in emails seen by Which? he was offered £50 as a gesture of goodwill, after an Amazon customer service representative acknowledged he had tried “a number of times” to report unrelated reviews appearing under one listing. He declined.
“I’ve sent so many emails with examples – when something is as misleading as that it’s something their platform needs to deal with,” he said.
“I don’t feel they’ve really been that interested in me taking the time out of my day to highlight things that are clearly wrong.”
Notes to editors
Between 21st February and 28th March 2022, Which? looked at the ten top-rated headphones on Amazon and analysed them for evidence of review merging. Product rankings on Amazon change on a continuous basis, so this investigation looked at just one snapshot in time.
The brands Which? found, in order of ranking*:
FSZBWL (had reviews for plushie dolls)
Hakdsy (had reviews for jigsaw puzzles)
LUECNG (had reviews for beach umbrellas)
Hakdsy (had reviews for engraved souvenir mugs)
UBBH (had reviews for razor blades)
WHJJK (had reviews for a keyboard desk tidy)
YOOUS (had reviews for glass pitchers/mason jars)
N/A (Bose) – no evidence of review merging on this listing
CATEDUS (had reviews for an extension cable)
WHJJK (had reviews for disposable paper bowls)
*Note: these brands are sold by more than one seller on Amazon, so Which? cannot determine whether these brands were implicated in any wrongdoing. Which? attempted to contact the sellers behind the individual listings and did not hear back. Which? asked Amazon to put it in touch with the sellers, but a spokesperson declined citing privacy reasons.
While review merging can be a legitimate way for a seller to tidy up and boost their catalogue of products, some unscrupulous sellers are deliberately gaming the system, Chris McCabe, a former Amazon employee who now runs an eCommerce consultancy, told Which?.
The sellers do this by either merging their own unrelated listings or hijacking dormant ‘zombie’ listings owned by other sellers, and re-topping them with their own product name. McCabe says it’s relatively easy to do and that there “aren’t enough safeguards in place” to stop it from happening.
While it can sometimes happen in error, deliberate and illegitimate review merging is a common “black hat” marketing tactic, designed to game the system, he said.
His colleague Leah McHugh, who is also an Amazon marketplace specialist, explained that the tactic works because sellers know that most shoppers won’t spend much time reading the reviews – especially beyond the first page.
“It harms consumers as well [as legitimate businesses] because a lot of people won’t look back through the older reviews, they’ll just assume all of these reviews are for the product – which of course is why people are doing it,” she said.
Rights of reply
Statement attributable to an Amazon spokesperson: “Amazon groups customer reviews for product variations like colour and size, and we have clear guardrails in place to prevent products from being incorrectly grouped, either due to human error or abuse. Our proactive measures detect and block the vast majority of abuse in our store automatically; however, we are disappointed when bad actors evade our systems, and we will continue to innovate and invest in our tools and processes. If we discover detail pages with incorrectly grouped reviews, we use these learnings to improve our prevention mechanisms. We have now taken appropriate enforcement action against the product listings and sellers in question.”
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