Bribery, hacking and gaming the system: the tactics used to post fake reviews online

Unscrupulous sellers are staying one step ahead of Amazon by using a range of tactics to beat the online retailer’s security systems and mislead shoppers with fake reviews, a Which? investigation has revealed.

The consumer champion scrutinised thousands of listings with the help of an Amazon expert to uncover how features designed to make the website more user-friendly are being abused on a grand scale.

Which? also reviewed almost 90 reports of issues with fake reviews it has received in recent weeks – including sellers offering buyers bribes of cash and gift vouchers in return for dishonestly boosting a review to five stars. 

A tactic employed by some sellers is the hacking of genuine Amazon accounts to post fake reviews – in one case a single account was used to post thousands of fake reviews. Some victims have been told they must manually remove fake reviews posted in their name.

Fakers are also exploiting an Amazon feature called “product variation”, which is used by legitimate sellers to group reviews for the same product in one place when it is available in different sizes and colours.

However, unscrupulous sellers are creating false variations, allowing them to artificially multiply the number of positive reviews attributed to a product while evading detection.

Which? found a pair of SDFLAYER headphones with 40 different meaningless colour variations (‘cxas021’ / ‘cxas014’ / ‘cxas012’, etc.) that enabled the seller to coordinate a steady stream of fake five-star reviews without Amazon’s systems flagging any suspicious activity on the product. Worryingly, this SDFLAYER item topped the headphones search listings at the start of June 2019.

Another feature, known as “product merging,” is used by legitimate sellers to bring together the reviews of similar items under one listing – tidying up their online shops and making it easier for shoppers to find all relevant reviews in one place.

However, Which? found examples of sellers taking advantage of this feature by merging dormant or unavailable products with new or existing product listings as a way to transfer positive reviews from one product to another. 

In one case, the consumer champion found reviews for a soap dispenser and a phone screen cover listed under a pair of headphones to artificially boost the product’s rating. 

Which? even found a smartwatch with 938 reviews dating back to 2011, despite having been first listed for sale in January 2019.

In 2018, Which? went undercover to reveal the Facebook ‘review factory’ groups with tens of thousands of members that are designed to act as a marketplace for fake reviews, generating incentivised positive ratings for products listed on Amazon. Despite reporting the issue to Facebook, as recently as last month Which? found review groups that were still highly active, with 133 new posts in just an hour on one group. 

The Competition and Markets Authority (CMA) has now announced that Facebook and eBay must tackle the sale of fake reviews through their sites. Facebook informed the CMA that the reported groups had been removed.

But a quick search reveals dozens more in their place, with thousands of members. Which? easily found more than 20 clearly labelled groups offering products for incentivised reviews shortly after.


Natalie Hitchins, Which? Head of Home Products and Services, said:

“Our investigation shows the lengths that unscrupulous sellers will go to to constantly pull the wool over the eyes of shoppers.

“Writing or commissioning fake or incentivised reviews is in breach of consumer law and can lead to criminal action against the individuals responsible. It is unacceptable that consumers continue to be misled into buying poor quality or even unsafe products by the current system of reviews and rankings.

“Online platforms must do more to tackle fake reviews, going above and beyond the current approach. If they fail to put more rigorous systems in place, then the CMA must intervene to ensure that fake reviews and other misleading tactics can be stamped out.”


Which? advice for spotting fake reviews:

  • Be wary of brands you don’t know – Scrutinise customer reviews more thoroughly than usual if you’re looking to buy a brand you don’t recognise, as our research indicates they are significantly more likely to be affected by fake reviews.
  • Be suspicious of large numbers of reviews – If you see hundreds or even thousands of reviews – be suspicious, especially if they are largely positive.
  • Look for repetition – If you see the same review titles, repetitive phrases or even the same reviewer name appear more than once on a product, it’s very likely that it has been targeted by fake reviews.
  • Watch out for multiple product variations – Look out for multiple variations of the same product within a single listing, especially if they have an obscure name. It’s unlikely that there are more than 10 variants of a pair of headphones. You can find out which variation is being reviewed underneath the date of the review.
  • Filter to check for unverified versus verified reviews – Reviews marked as ‘verified’ are those that Amazon can confirm were left after the item was purchased through its website. Unverified reviews are therefore far easier to ‘fake’ – in that they could be written by someone who has had no experience at all with the product.
  • Look at the dates – If large numbers of reviews were posted on the same day, or in a short period of time, it’s very likely that they are fake – especially if they are also unverified.
  • Check seller profiles – Things you might be wary of are foreign seller locations, strange business names, a lack of contact details, and of course, negative reviews of the seller. Check out the seller profile page before you buy to see if anything seems out of place.

For more tips for avoiding suspicious reviews, see the Which? guide on how to spot fake reviews – 



  • In June 2019, Which? investigated the top 20 products in popular home technology categories on Amazon to uncover the tactics that some sellers use, unbeknownst to Amazon, to artificially boost the ratings of their products. Since its investigation into fake reviews in April 2019, Which? has also received almost 90 reports of issues with fake reviews – including buyers offered bribes of cash and gift vouchers in return for dishonestly boosting a review to five stars. 
  • Which? found examples of sellers bribing customers:
    • One customer received eight requests from a seller to change a three-star rating to a five-star rating on a solar floodlight from a manufacturer, offering a partial refund in exchange.
    • Another customer bought a product that ‘didn’t work at all’ and left a suitable review. The seller offered a £25 Amazon gift card to remove the review.
  • Which? heard from Amazon customers who had been victims of account hacking, with one explaining that their account was hacked and used to leave 2,552 reviews across a variety of products.
  • In a recent investigation Which? found thousands of potentially fake or suspicious reviews across popular technology and household products on Amazon.
  • Which? has found evidence that unscrupulous businesses are finding ways to manipulate average product ratings with verified reviews. In a follow up to its investigation into Amazon ‘review factories’ on Facebook, the consumer group found that four out of five Facebook groups from the investigation were still facilitating the incentivised and paid-for Amazon reviews, raising more questions about how reliable customer reviews are – as highlighted in another recent investigation.





Any attempt to manipulate customer reviews is strictly prohibited at Amazon. 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. We have clear participation guidelines for both reviewers and selling partners and we suspend, ban, and take legal action on those who violate our policies.

We use a combination of teams of investigators and automated technology to prevent and detect inauthentic reviews at scale, and to take action against the bad actors behind the abuse. We estimate more than 90% of inauthentic reviews are computer generated, and we use machine learning technology to analyze all incoming and existing reviews 24/7 and block or remove inauthentic reviews. Our team investigates suspect reviews, works with social media sites to stop inauthentic reviews at the source, pursues legal action to stop offenders  from planning reviews abuse, and feeds new information into our automated systems so it continues to improve and become more effective in catching abuse. 

We work hard to enrich the shopping experience for our customers [and selling partners] with authentic reviews written by real customers. Customers can help by reporting any requests they get to manipulate reviews to customer service.



From time to time, customers may receive e-mails appearing to come from Amazon, which are actually false e-mails, sometimes called ‘spoof e-mails’ or ‘phishing e-mails’. These can look similar to real Amazon e-mails but often direct the recipient to a false website where they might be asked to provide account information such as their e-mail address and password combination.

The best way to ensure that you do not respond to a false or phishing e-mail is to always go directly to your account on Amazon to review or make any changes to your orders or your account. Customers can access their account by visiting and clicking on the ‘Your account’ link in the top right hand corner of any page.

We would ask any customer who believes that they have received a false or phishing email to alert us via our e-mail address.

For more information including a video to help you identify whether an email is from Amazon, please visit

You can read more about this here.



A Facebook spokesperson said: “Fraudulent activity is not allowed on Facebook, including the trading of fake reviews, and we have removed all of the groups Which? reported to us. We know there is more to do to tackle this issue, which is why we’ve tripled the size of our safety and security team to 30,000 and continue to invest in technology to help proactively prevent this kind of abuse.”


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