Amazon sellers boost listings with reviews from different products

The consumer watchdog 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 loophole 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. Bose was the only established brand across the top 10 headphones which 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.

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.

Says 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.”

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

Says Rocio Concha, Which? Director of Policy and Advocacy:

“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.”