From Reviews
to Revenue
How Star Ratings and Review
Content Influence Purchase©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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Contents
3Introduction

18

The Effect of the Number of Reviews

4

Perfect is Too Good to Be True

20

4 Recommendations for Brands
and Retailers

11

The Importance of Star Ratings forMore Expensive Items

21

About the Study and PowerReviews

13

The Influence of Star Ratings in HighConsideration Categories

21

About Spiegel Digital and Database
Research Center©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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IntroductionIt’s largely understood that ratings and reviews play a big role inconsumers’ purchase decisions. In fact, previous PowerReviews
research found that the presence of ratings and reviews is oneof the top factors impacting purchase decisions—second only
to price . But what’s less obvious are the circumstances underwhich reviews have the biggest impact on purchase.

probability of sales. For three months, the Northwestern
research team examined:• The relationship of average star rating and purchaseprobability• The effect of average star rating on products at different
price points within the same category
PowerReviews recently partnered with Northwestern • The interaction of length and number of reviews on sales
University’s Spiegel Digital and Database Research Center
to better understand the influence of ratings and reviews This report helps brands and retailers answer the question,
as a whole and the role various review elements play on the “How do reviews influence purchase?” as well as understandhow to best prioritize their efforts.
11

PowerReviews (2014): The Proven Power of Reviews.

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Perfect is Too Good
to Be True

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A 5 Star Rating Isn’t the BestIt may seem obvious that the higher a product’s average star
rating, the more likely a person is to purchase it. But theNorthwestern research team found that the relationshipbetween the average star rating of a product and its sales is
not linear. Simply stated, the likelihood of a product being
purchased doesn’t necessarily increase as its star rating
increases.

Purchase likelihood then peaks when the average star ratingof a product is between 4.2 and 4.5 stars and starts to drop as
the star rating approaches a perfect 5. A shopper is more likely
to purchase a product with an average star rating between 4.2
and 4.5 than one with a 5 star rating.

As the graphs that follow show, there is some variation within
categories, but the conclusion is the same: a perfect 5 starIn general, the number of stars has little effect on purchase rating is not the most desirable.
when the rating is between 1 and about 3 stars. But when thestar rating surpasses 3, so does likelihood of purchase. In otherwords, a customer is more likely to purchase a product with a
4 star rating than one with 3 stars.

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Lightbulbs
Most likely
to purchase
4.5

Least likely
to purchase
12

3

4

5

Average Star
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Hair Color
Most likely
to purchase

4.2

Least likely
to purchase
12

3

45

Average Star
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Salon Haircare
4.4

Most likely
to purchase

Least likely
to purchase
123

4

5

Average Star
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Negative Reviews Establish Trust

Why do purchases drop off once the average star rating
surpasses 4.2-4.5? The Northwestern research team believes
this is because consumers perceive ratings closer to a perfect
5.0 as “too good to be true.” As counterintuitive as it may
seem, negative reviews have a positive impact because theyhelp establish trust and authenticity. Consumers understandthat a product can’t be all things to all people, and they
appreciate negative reviews as an important element in theirdecision-making process. In fact, previous PowerReviews
research found that 82% of shoppers specifically seek out
negative reviews.1

1

PowerReviews (2014): The Proven Power of Reviews.

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4.2-4.5 is the ideal averagestar rating for purchase probability©PowerReviews. All Rights Reserved 														2015 From
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for More Expensive Items©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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Reviews Matter for High Priced Items

Previous PowerReviews research found that reviews are mostimportant for big-ticket items like appliances, electronics andcomputers.1 In this study, the Northwestern research team
took a different angle, studying the effects of star ratings on
low and high priced products within the same category—even
a relatively low priced category like hair care products.

Northwestern segmented products within each category intolow-priced and high-priced items and found that star ratings
had a stronger influence on expensive items compared tothe cheaper items within the same category. For example, acheaper hair conditioner with a low average star rating is more
likely to be purchased than an expensive hair conditioner withthe same low rating.

1

PowerReviews (2014): The Proven Power of Reviews.

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The Influence of Star Ratings inHigh Consideration Categories©PowerReviews. All Rights Reserved 														2015 From
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13

Where Reviews Matter Most
High consideration items:• Expense• Safety• Unknown product• Unknown brand©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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14

Reviews Matter for HighConsideration Categories

The team also studied the level of involvement or considerationfrom a consumer’s perspective when purchasing products in acategory. For the purposes of this study, high consideration
products are defined as products that consumers think more
about buying because of:• Higher price• Safety• New brand or productThe study found that star ratings are most impactful for
expensive products within high consideration categories.

Reviews Mitigate Risk

What all these factors have in common is risk; purchasing
the product requires careful consideration of economic
investment, family safety, or personal identity. A consumer
may not ordinarily seek out reviews for cereal or shampoo,
but if it is a new brand or is higher priced within its category(think organic), more information — in the form of reviews —can strengthen consumers’ confidence in a product, leading
to a greater willingness to pay for it. Reviews, then, can beespecially important when launching new products or newbrands.

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Baby Food
Most likely
to purchase

Least likely
to purchase
12

3

4

5

Average Star
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Weight Loss
Most likely
to purchase

Least likely
to purchase
12

3

4

5

Average Star
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The Effect of theNumber of Reviews©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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The Ideal Number of Reviews Varies

Most shoppers need a little nudge to write a review. But how
many reviews does it take to impact purchase likelihood?
The short answer? It depends. The Northwestern researchteam found that the ideal number of reviews depends on thelength of the reviews themselves. When reviews are shorter,
more reviews matter. When reviews are longer, however, thenumber of reviews has a less significant impact.
Long Reviews
More reviews are less
impactful on sales

Short Reviews
More reviews drive sales©PowerReviews. All Rights Reserved 														2015 From2015Ratings
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4 Recommendations for Brands and Retailers

The findings of this study point to some practical recommendations for brands and retailers looking to generate resultsfrom ratings and reviews and prioritize their efforts appropriately.

12

3

4

Embrace Negative
Reviews:

Prioritize Higher Priced
Items:

Consider Sampling for
Generate More Reviews:
New Brands or Products: The number of reviews for aYour knee jerk reaction may be
to reject negative reviews. But
the research from Northwestern
proves that this isn’t the best
course of action to drive sales.
While you certainly don’t want to
aim for negative reviews, allowing
them on your site brings authenticity to your review content andhelps you build trust with shoppers, especially because the vast
majority of consumers are actively seeking out negative reviews.

There’s a higher risk involved withpurchasing a higher priced item.
Reviews can help consumers
overcome this risk, so make these
expensive items a higher priority.

As the study found, reviews
matter when the likelihood of aconsumer purchasing a product isinherently low. This is especiallytrue when a brand or product isrelatively unknown, or when the
product is completely new in anexisting category. When a new
product or brand is launched into
an existing category, it makes
sense, then, to actively seek out
reviews from consumers. Productsampling can allow brands to generate reviews for new products,
which can mitigate risk for futurebuyers and lead to more sales.

©PowerReviews. All Rights Reserved 												product can have an impact onsales, especially if those reviews
are short. Take a look at yourreviews data, and identify products where reviews are generally
short. Studies show that up to
80% of reviews originate frompost purchase emails, so be sure
to send an email to shoppers asking them to review their purchas2
es . Make the process as simple
as possible to generate the mostreviews.
2PowerReviews Internal Data		

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About this Report

This report is based on 2015 research conducted by Northwestern University Spiegel Digital and Database Research Center and commissioned by PowerReviews. The Northwestern research team analyzed ratings and reviews data in the consumer packaged goods industry for thisstudy. The data analyzed comes from multiple ecommerce websites, including 22 product categories with a total of 111,460 SKUs.

About PowerReviews

PowerReviews is the choice of more than 1,000 global brands and retailers to collect and display customer ratings andreviews on more than 5,000 websites. An essential resource for consumers as they search and shop online and in-store,
ratings and reviews drive relevant traffic, increase sales, and create actionable insights to improve products and services.

About Spiegel Digital and Database Research Center

The focus of the Spiegel Research Center is to do evidence-based, data driven analysis to prove the relationship between customer
engagement and purchase behavior. The Center’s research focuses on consumer behavior in social media and on mobile devices.

www.powerreviews.com
info@powerreviews.com									@PowerofReviews						+1 312-447-6100 | +1 844-231-7540 | +44 (0)20-7152-4452
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