PEOPLE are twice as likely to buy poor-quality products online if they have been boosted by a fake review, a 'groundbreaking' behavioural experiment has revealed.

The study is expected to give new impetus to an investigation being carried out by the UK Competition and Markets Authority (CMA) into fake and misleading reviews on several major websites - as consumer flock online to do their shopping with high streets shut due to the coronavirus lockdown.

Which?, the consumer organisation which carried out the research says it shows how the regulator must take the "strongest possible action" against sites that fail to tackle the problem.

The group carried out a shopping task test of 10,000 people to discover how fake reviews affected their behaviours.

And the researchers found that every single one of the fake review scenarios it tested had adverse effects on consumer behaviour and, in the worst instance, demand for products boosted by these techniques increased by more than 136 per cent.

The CMA is examining whether online shops were "doing enough" to protect customers as they turn to online shopping during lockdown.

Some reviewers are known to have been offered money or other incentives in exchange for positive comments.

But fake and misleading reviews are illegal under consumer protection law - which bans traders from pretending to be consumers of their own products, for example.

Last year the CMA estimated that estimated that online reviews potentially influence £23bn of UK customer spending every year.


Which? said it believes that review platforms must take more responsibility and make improvements to their systems to halt the "scourge" of fake reviews and stop consumers from being manipulated.

Caroline Normand, Which? director of advocacy said: "“We have found categorical evidence that people are at huge risk of being misled by fake reviews, which is particularly worrying given people are shopping online more than ever during the coronavirus pandemic.

“Online platforms must put more effective measures in place to stop unscrupulous sellers gaming the system with ease, otherwise the CMA needs to take strong action against these major sites.”

People taking part in the survey were asked to pick one of three product types, headphones, dash cams or cordless vacuum cleaners, where that was previous evidence of fake reviews.

They were then randomly allocated into one of six groups to determine the type of fake review activity they would see, varying from inflated star ratings to false review text - tactics commonly used by unscrupulous sellers - as well as the addition of a platform endorsement label, which can often be influenced by high review ratings.

Participants were shown five identically-priced products in their chosen category: a Which? Best Buy, three ‘fillers’ with mediocre reviews and a Don’t Buy which may or may not have been manipulated by fake reviews.

They reviewed the information about the five products, including seven reviews for each, before deciding which they would most like to buy in real life.

In the group that saw no fake reviews, one in 10 people (10.5%) chose a Don’t Buy product.


But in the group where fake review text was added to this product, with phrases such as "oh...WOW! I love when I'm about to review an awesome product" alongside inflated star ratings pushing it up the search results, the numbers who wanted to buy doubled.

Consumers have registered their concerns about the fake review scam to the organisation.

Jeff, 72, wanted to buy a thermometer off an online marketplace in order to check himself for potential Covid-19 symptoms.

He told said: "Conventional thermometers were in very short supply but there were posh looking ones with rave customer reviews so I selected the one with the most five-star reviews.

"It arrived promptly and an £8 voucher was included, valid if I too gave the thing a five-star review. When I tried it out it didn't work. At least, if I took my temperature five times, it decided I was five different people, with temperatures ranging all over the place. I decided to return the thermometer and the voucher.


"I'm furious that companies are allowed to tout for five-star reviews in this way. Reviews used to be so dependable and balanced: often you'd see only negative reviews. These days it all looks like marketing."

Which? worked with research consultancy The Behaviouralist, to produce experimental evidence of how consumer behaviour changes in the presence of fake reviews.

Last year, the consumer group Which? said that in the space of a single month, it had found 55,000 posts offering free products to those who wrote good reviews on Amazon.