THE COUNT
More reviews, steadier average
The number of reviews shows how precise the average is. A 2017 study found people often failed to weigh this, sometimes picking the item likely to be worse.
Weigh a ratingWHAT THE RESEARCH SAYS
Read past
the stars.
A star rating is an average, not a verdict.
How many people gave it matters as much as the number itself. Research shows shoppers often misjudge that, and the UK competition regulator suggests the middle reviews are the ones to read.
Weigh a rating Read the short answer
01 Count the reviews02 Read the middle stars03 Look in more than one placeBetter choices from the same stars
THE SHORT ANSWER
The count
carries the weight.
Two numbers sit beside every rating:
the average and how many people gave it.
THE TOP
Perfect can put people off
Across more than 40 product categories, purchase likelihood peaked at 4.2 to 4.5 stars and fell as ratings approached a perfect 5.
See the numbers
THE MIDDLE
Read the 3s and 4s
The CMA says a 3 or 4-star review is unlikely to be fake, so it can be particularly useful. A small gripe may not matter to you.
How to read themA QUICK RATING CHECK
How much does
this rating tell you?
Pick what you see on a listing. The bar shows how much weight research and regulator advice suggest it can bear on its own.
Based on Powell and colleagues (2017), the Medill Spiegel Research Center (2021) and CMA tips (2026). General consumer information.
TWO NUMBERS WORTH KNOWING
Stars move money,
but not in a straight line.
One figure on where buying peaks,
one on how much spending reviews touch.
THE PEAK · MEDILL SPIEGEL
Average rating where purchase likelihood peaked
4.2–4.5 stars
Northwestern University's Medill Spiegel Research Center found purchase likelihood peaked in this range across more than 40 categories, then dropped as ratings approached a perfect 5.
THE STAKES · CMA
UK spending potentially influenced each year
£23 bn
The Competition and Markets Authority estimated that as much as £23 billion a year of UK consumer spending is potentially influenced by online reviews, across six broad sectors.
The CMA also cites Which? research that 89% of consumers use online customer reviews when researching a product or service.
FOUR HABITS TO TRY
Two minutes,
a better read.
None of these takes long. Together they turn a single number into a fuller picture of what other people found.
- Look at the count firstBefore comparing averages, check how many reviews sit behind each. A handful of reviews gives a shaky average.
- Read, do not just scanThe CMA says shoppers too often trust 5-star ratings without reading what people say. Some reviews are vague or about the wrong item.
- Start in the middleRead the 3 and 4-star reviews. Decide whether the small complaints matter to you.
- Check another siteThe CMA suggests looking across several sites to spot patterns and get a consistent picture.
WHAT UK LAW NOW SAYS
Hidden reviews
are a banned practice.
Since April 2025, the Digital Markets, Competition and Consumers Act 2024 treats fake reviews and undisclosed paid-for reviews as banned practices, automatically deemed unfair and illegal.
The CMA says the rules also cover how reviews are handled, for example if negative reviews are hidden or if star ratings present an inaccurate picture. It can fine firms up to 10 percent of global turnover.
QUESTIONS PEOPLE ASK
Frequently asked
Is a higher star rating always better?
Not on its own. The number of reviews shows how precise the average is, and research found people sometimes preferred an item with more reviews even when a statistical model suggested the other was likely better.
Why might people distrust a perfect 5.0?
The Medill Spiegel Research Center found purchase likelihood peaked at 4.2 to 4.5 stars and dropped as ratings approached 5, suggesting negative reviews help establish trust.
Which reviews are most useful to read?
The CMA suggests 3 and 4-star reviews, which are unlikely to be fake. They often explain a small drawback you can judge for yourself.
How much do reviews matter?
The CMA estimated that as much as £23 billion a year of UK consumer spending is potentially influenced by online reviews.
Can a business hide its bad reviews?
The CMA says hiding negative reviews, or showing star ratings that give an inaccurate picture, is covered by the banned practices in force since April 2025.
SOURCES
Where the facts come from
Each figure on this page comes from the sources below. Check them for the full detail and context.
- Powell, Yu, DeWolf and Holyoak (2017): The love of large numbers, a popularity bias in consumer choice, Psychological Science (Europe PMC)
- Medill Spiegel Research Center, Northwestern University: Star ratings and review content (2021)
- GOV.UK (CMA): Fake and misleading reviews, businesses under CMA investigation (27 March 2026)
- GOV.UK (CMA): CMA secures important changes to tackle fake reviews (£23 billion estimate)
- GOV.UK (CMA): Undertakings to curb fake reviews and catalogue abuse