Top-rated Amazon headphones boosted by 'fake reviews' for toys, mugs and umbrellas

Nine out of the 10 top-rated Bluetooth headphones for sale on Amazon have been artificially boosted by unrelated reviews, including for an extension cable more than one person claimed smoked or caught alight, a new Which? investigation has found.

In some cases, some of the ranking of the headphones had been inflated by thousands of entirely irrelevant reviews, with none mentioning headphones at all.

Our research indicates these products leapfrogged up the rankings as a result of 'review merging' abuse.

Find out how to spot a fake review with our in-depth guide.

What is review merging?

Review merging can be a legitimate way for sellers to manage their catalogue when they have a close variation of an existing product to add to an existing 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's 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.

This suggests the problem may not just confined to the products we found in our investigation.

Merged reviews on Bluetooth headphones

We looked at Bluetooth headphones for sale, and arranged the results by 'average customer reviews', to mimic how a consumer might shop when looking for the best-rated headphones on the site.

There was just one established brand across the top 10 - Bose, which appeared 8th, and showed no signs of review abuse. The others were relatively unknown brands, which did not appear to be sold on any other sites except for Amazon.

Each of these unknown brands had reviews for entirely different products - including umbrellas, personalised jigsaw puzzles, bowls, jars, an extension lead and a keyboard desk tidy. We attempted to contact the sellers about our findings, but they did not respond.

We also found a similar 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.

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Merged listings included 'Amazon's Choice' products

Surprisingly, two of the nine artificially boosted listings we found had earned the coveted Amazon's Choice badge, despite being inflated by clearly illegitimate reviews - in one case for a stuffed bear, and in another for an extension cable more than one person claimed had smoked or caught alight.

The headphones that ranked most highly in the list, and were first to be labelled Amazon's Choice, included 40 reviews in total - none of which were for the product at all. All of the reviews, including three clearly showing that the product was not a pair of headphones, were for plushie toys - a 'cute' and 'adorable' cuddly stuffed bear, apparently loved by children and adults alike.

'She's more of a decorative plushie than a cuddling one, but definitely worth the purchase,' said one reviewer. 'She is wonderful! I love her so much!' said another.

The second pair of headphones to be labelled Amazon's Choice were entirely populated by reviews for an extension lead several shoppers claimed could be a fire hazard.

We found no mentions of headphones or earbuds in any of the 207 reviews, while all nine photo reviews showed an extension lead. Most of the reviews for the product were five stars and beneficial to the rating of the headphones, but several reviewers, based in the US, claimed the extension lead was unsafe.

• 'I think I got lucky though that it only damaged some items vs. catching fire and burning my house down. I 100% believe the other reviewers who describe melting/burning/fires when using this product,' one reviewer said.
• 'DO NOT BUY THESE!!!!! YOUR HOUSE COULD BURN DOWN!!!' claimed another.
• 'Save yourself time, money and grief and a potentially dangerous situation,' claimed a third person.

While we cannot know whether the original product in question was in fact a fire hazard and unsafe, we were nevertheless surprised to see such obviously irrelevant reviews on a listing for Bluetooth headphones.

Fortunately, Which? has you covered if you're looking for a genuinely good pair of Bluetooth headphones. Read our reviews of headphones to see our top-rated products.

Personalised jigsaw puzzles, paper bowls and glass jars

All other seven headphone listings in the top 10 that were for unknown brands carried irrelevant and unrelated reviews, too. One was boosted by 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. We didn't find one review that mentioned earbuds or headphones on that listing.

'Only one earphone works!!' and 'Absolute waste of money' were the only two headphone-related reviews on another listing, which had 1,350 reviews for mason jars and glass pitchers.

The other brands were boosted by irrelevant reviews for cups, razors blades, a keyboard desk tidy, and disposable bowls.

We tried to get in touch with the sellers to ask them about our findings, but we did not receive any responses. We also asked Amazon to put us in contact with the sellers directly, but a spokesperson declined citing privacy reasons.

A 'black hat' tactic designed to game the system

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. We spoke to Chris McCabe, a former Amazon employee who now runs an eCommerce consultancy, to find out more.

'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 said, adding that in his view it's relatively easy to do and that and 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.

Amazon customer taken in by review merging

Alistair Soames, aninvestment manager from Surrey, had a similar experience when he was shopping for earbuds on Amazon in 2019. After some digging, he noticed some of the products were boosted by reviews for entirely different products.

'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 a 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.'

Reporting fake reviews to Amazon

We wanted to find out what a consumer could do if they spotted an irrelevant review. Amazon encourages those who spot fake or suspicious reviews to report them using its 'Report Abuse' function. To test this, we reported the irrelevant reviews.

We waited a week after finding the merged examples on headphones to give Amazon a fair chance of taking action without a prompt, and then reported the first page of incorrect reviews. At this point, one of the listings had disappeared, but all the others remained unchanged, with all of the suspicious reviews still showing.

We checked the listings again after a period of four weeks, to see if Amazon had taken any action. Three of the listings we reported for abuse still had clear signs of review merging and were still available for sale.

These were the headphones boosted by reviews for an extension lead (which received the Amazon's Choice badge after we reported it), the headphones with reviews for a keyboard desk tidy, and the headphones displaying reviews for jigsaw puzzles.

One listing was deleted entirely. Two remained but with all the reviews deleted. The other three were marked 'unavailable' - but they still displayed all the reviews we'd reported.

Amazon's response: we block 'majority' of abuse

We shared our findings with Amazon and were told it had since taken action against the sellers featured in our investigation.

A spokesperson said Amazon proactively blocks the 'majority' of abuse on the platform.

'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,' the spokesperson said.

'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.'

Which? calls for better enforcement

Which? believes Amazon needs to better enforce its own policies, particularly given that Which? first raised concerns about review merging back in 2019. Amazon 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.

Rocio Concha, Which? director of policy and advocacy, added: '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.