The Power of the Stars: How Online Reviews Influence Purchasing Decisions

A Tuesday evening, the heating has broken down. Three heating contractors nearby, all with websites, all with similar prices. What makes the difference is not the prettiest homepage, but the star rating: 4.7 from 180 reviews, the latest from last week. The competitor with 4.9 stars from eight reviews, the most recent two years old, does not get the call.

This is how millions of decisions are made today. This article brings together the most important studies from Germany and the United States: how strongly reviews influence purchasing decisions, in which industries they matter most, what customers expect today, and how many businesses are already using reviews strategically. At the end, there is a practical checklist.

Reviews are the new word of mouth

Online reviews are now an integral part of almost every purchasing decision. According to the Local Consumer Review Survey 2026 by BrightLocal, 97 percent of US consumers read reviews of local businesses. Forty-one percent now do so for every search, compared with just 29 percent a year earlier.

The picture is equally clear in Germany. A representative Bitkom survey shows that customer reviews are the most important source of information before a purchase for 55 percent of online shoppers. By contrast, only 47 percent use price comparison websites.

Not just a matter of age

Younger people read reviews most frequently, but older people rely on them too. The Bitkom figures by age:

This applies not only to products in online stores. According to a GfK survey commissioned by Greven Medien, 56.4 percent of Germans search for online reviews before buying something or hiring a service provider.

Strangers are trusted almost as much as friends

Almost one in two people (49 percent) trust online reviews as much as a personal recommendation. In a survey by PowerReviews, 96 percent consider reviews important when making purchasing decisions, compared with just 72 percent for recommendations from family and friends. According to Capterra, 39 percent of German consumers trust online reviews most, while only 23 percent trust recommendations from friends.

Six platforms instead of one

Consumers do not rely on a single source. On average, they use six different review platforms before choosing a business. Google remains the largest point of reference, but is losing weight: 71 percent use Google for reviews, compared with 83 percent in 2025. Specialized platforms, mapping services, and video platforms are gaining ground. For businesses, this means that those with a presence only on Google fail to reach many people searching.

How strongly reviews influence purchasing decisions

Reviews work in both directions—and powerfully so. Positive reviews make 85 percent of US consumers more likely to become customers, while negative reviews deter 77 percent (BrightLocal 2026). Ninety-three percent have bought something at least once after reading reviews. Twenty-seven percent spent more than US$1,000 in the process.

Just a few reviews can make the difference

The best-known figure comes from the Spiegel Research Center at Northwestern University. The researchers analyzed real purchasing data from online retailers across more than 22 product categories and over 100,000 items. Their result: A product with five reviews is 270 percent more likely to be purchased than one with none at all.

Most of the effect is already generated by the first ten reviews, especially the first five. Conversely, without reviews there is no proof of trustworthiness. Fifty-seven percent of consumers will not buy a product if it has no online reviews (PowerReviews 2025).

The more expensive it is, the more important reviews become

Reviews matter more when the risk of making a bad purchase is higher. According to the Spiegel Research Center, reviews increase conversion by 190 percent for low-priced products and by 380 percent for expensive ones. This explains why reviews carry so much weight for tradespeople, doctors, real estate agents, and financial service providers.

One more star generates measurable revenue

How reviews directly affect revenue was examined by Michael Luca of Harvard Business School. He compared the sales data of all restaurants in Seattle with their Yelp ratings. The result: One additional star brings independent restaurants 5 to 9 percent more revenue. The effect did not appear for chains because their brands are already well known.

This is an important message for small and medium-sized businesses. Those without a recognizable brand benefit most from a good reputation online.

Reviews are often the beginning, not the end

Not everyone buys immediately after reading reviews. Following positive reviews, 66 percent continue researching, while 34 percent are immediately ready to buy or book. The most common next stop, at 54 percent, is the company’s website, compared with just 32 percent in 2019. Reviews therefore bring customers to a company’s own site, where the offering and contact options must convince them.

What customers expect today: more stars, more reviews, more recent content

Expectations are rising quickly. A review profile that was still sufficient in 2025 may already look weak in 2026. The most important thresholds from the BrightLocal Survey 2026:

Without volume, there is no trust

A handful of reviews is no longer enough. Forty-seven percent of consumers avoid businesses with fewer than 20 reviews. Only 9 percent would choose a business with five or fewer reviews. A large number of reviews acts as social proof and reduces perceived risk.

According to BrightLocal, the single most important criterion is corroboration: 56 percent pay attention to whether a review is supported by others with a similar message. A single glowing review is hardly convincing; a recurring pattern is.

Old reviews lose their value

Seventy-four percent of US consumers look only at reviews from the past three months. Eighteen percent are influenced only by reviews from the past week. In Germany, Capterra showed a similar picture as early as 2020: 40 percent read only reviews no more than three months old.

The reason is obvious. Staff, offerings, and service change. A review from 2023 says little about a visit next week.

Perfect looks suspicious

As important as high star ratings are, 5.0 is not the ideal. The Spiegel Research Center found that the likelihood of purchase is highest for average ratings between 4.0 and 4.7 stars. As the average approaches 5.0, it falls again. According to PowerReviews, 46 percent consider a perfect five-star rating suspicious; among Generation Z, the figure is as high as 53 percent.

Critical voices are therefore part of the picture. According to Capterra, 46 percent of Germans specifically check whether a provider also has negative reviews. What matters then is how the business responds.

The industries where reviews matter most

Reviews have an impact everywhere, but not with equal strength. Consumers most often read reviews of restaurants, hotels, doctors’ offices, auto repair shops, and clothing stores, in that order (BrightLocal 2020). This is complemented by industries in which a decision is expensive or difficult to reverse.

Restaurants: every star counts

Restaurants are the classic example of businesses that receive reviews. In Germany, they were reviewed twice as often in 2023 as in the previous year, according to an analysis of more than 2,800 restaurants by Re:spondelligent. Of all reviews, 67.8 percent awarded five stars, while only 5.3 percent awarded one star.

Hotels: far more than Google

Hotels have the most widely distributed review environment. According to Birdeye, only 38 percent of their reviews appear on Google. The rest are spread across Booking.com, Tripadvisor, Expedia, and other platforms. Businesses that maintain only one profile see just a fraction of what guests read.

Doctors: reviews influence decisions

Reviews also play a major role when choosing a doctor. According to the Bertelsmann Foundation’s Weisse Liste, 60 percent of portal users have already chosen a particular doctor because of reviews, while 43 percent have decided against one. A study commissioned by jameda reached a similar conclusion: Around 70 percent of readers of doctor reviews subsequently decided for or against a doctor.

Trades: trust at the front door

Anyone hiring a tradesperson lets a stranger into their home and often pays a great deal of money. Customers therefore look very closely. In the United States, the volume of reviews for home services recently grew by 24.5 percent. Good, recent reviews give trades businesses a direct competitive advantage over competitors with few or outdated reviews.

Responding to reviews: customers expect it, many businesses remain silent

How a business responds to reviews is almost as important as the review itself. Eighty-nine percent of consumers expect businesses to respond. Eighty percent are more likely to choose a business that addresses all reviews. Forty-two percent avoid businesses that ignore their reviews completely (BrightLocal 2026).

The gap in Germany

In Germany, expectations and reality are far apart. According to Capterra, 91 percent of Germans read businesses’ responses to reviews. At the same time, 38 percent have never received a response to one of their own reviews. A later Capterra study confirms the pattern: 85 percent read business responses, while 40 percent have never received one.

Businesses that respond therefore stand out. And a response is not addressed only to the person who wrote the review. It is read by every future customer who visits the profile.

Quick and personal

Expectations regarding response times are rising. Nineteen percent of US consumers expect a response on the same day, compared with 6 percent a year earlier. Eighty-one percent expect a response within one week.

At the same time, a quick platitude is not enough. Standardized copy-and-paste responses deter 50 percent of consumers. Businesses that receive many reviews therefore face a dilemma: individual responses take time. AI-supported response suggestions, reviewed and adapted by a human, are increasingly solving this problem. According to Birdeye, around 60 percent of responses from businesses with professional review management are written by people and 40 percent are automated.

Respond to every review, not just the negative ones

Many businesses respond only to criticism. That is not enough: If a business responds only to negative reviews, 47 percent would be more likely to choose it. If it responds to all reviews, the figure is 80 percent. A brief thank-you for a positive review shows that someone is listening.

How many businesses use reviews proactively

Many businesses have yet to tap this potential, especially in Germany. According to a Capterra study of German SMEs, only just under half (46 percent) receive online reviews at all. Of these businesses, 74 percent actively manage and use their reviews. Thirty-nine percent often respond to reviews, but only 20 percent always do so.

The basics are often missing, too. In the United States, according to BrightLocal, only 35 percent of small and medium-sized businesses have a Google Business Profile. Without a profile, customers can neither read nor write reviews there.

Those who ask receive reviews

The most effective lever is surprisingly simple: ask customers. Seventy-eight percent of US consumers have been asked by a business to leave a review in the past twelve months. A large proportion comply; according to BrightLocal, at least 65 percent subsequently wrote a review. Twenty-eight percent even say they always write a review when asked, compared with 16 percent in 2025.

The willingness is there. Ninety-four percent are generally open to writing a review. Yet only 69 percent actually did so in the past twelve months. A targeted request at the right moment closes the gap between willingness and action.

A figure from e-commerce shows how effective such requests can be: Up to 80 percent of product reviews result from follow-up emails after purchase (Spiegel Research Center, based on PowerReviews data).

Professionals automate

Businesses with professional review management have long since automated the process. According to the State of Online Reviews 2026 by Birdeye, around 95 percent of review requests are sent automatically by email and SMS. The request goes out after the appointment, purchase, or service visit, without anyone having to remember it.

The result is measurable:

• Review volume grew by 30.7 percent in 2025, the strongest increase since 2021.

• A record 75.5 percent of all reviews received a response.

• A total of 79.8 percent of reviews contained text, not just stars.

Important context: These figures come from Birdeye customers—that is, businesses already investing in review management. They show what is possible, not the average across all businesses.

Beware of incentives

Not every method is permitted. Eleven percent of US consumers were offered something in return for a positive review. This violates the policies of Google and many platforms and is now also illegal in the United States. The same applies in Germany: Businesses that buy reviews or specifically approach only satisfied customers risk warnings, legal action, and a loss of trust.

New rules of the game: AI is listening now

The biggest change of the past two years has come from artificial intelligence. Forty-five percent of US consumers now use AI tools such as ChatGPT for recommendations about local businesses, compared with 6 percent a year earlier (BrightLocal 2026). This makes AI tools the third most common source of recommendations after Google and Facebook.

Summaries instead of individual reviews

Google, Amazon, and other platforms are now summarizing reviews using AI. Eighty-two percent of consumers read these summaries, while 23 percent rely on them exclusively. Only 18 percent ignore them.

This changes what matters. An AI does not summarize individual reviews but patterns: “Guests praise the fast service but complain about waiting times on weekends.” Which patterns it recognizes depends on how many reviews there are, how recent they are, and how specifically they are worded.

What this means for businesses

AI systems such as ChatGPT, Gemini, and Perplexity base their recommendations on sources they trust. These include review platforms, business directories, and the company’s website. A business with many recent, detailed, and answered reviews across multiple platforms provides these systems with precisely the material they need to make a recommendation.

Trust in AI recommendations is already high. Forty percent of consumers trust AI platforms for business recommendations, while only 32 percent do not. Forty-two percent trust them as much as traditional reviews. Reviews are therefore not becoming less important; quite the opposite: They are the raw material from which AI builds its answers.

Authenticity: the foundation of every review

Reviews work only as long as people believe them. Fake reviews are therefore a problem for customers and honest businesses alike. Google alone blocked around 240 million reviews for policy violations in 2024.

Consumers have become more sensitive. Seventy percent have regretted a purchase despite having read reviews. Ninety-seven percent believe businesses with fake reviews should be punished. Fifty-seven percent want such businesses excluded from review platforms (BrightLocal 2026).

Platforms have a responsibility

Consumers place the main responsibility on the platforms: 63 percent expect review platforms to detect and prevent fake reviews. Forty-nine percent also see businesses themselves as responsible.

In Germany, the Federal Cartel Office examined more than 60 review platforms from 16 industries. Its conclusion: Alongside price, user reviews are often the key decision criterion when buying online. However, many platforms checked only with simple word filters or acted only after reports were submitted. The authority called on platforms to do considerably more to combat manipulation.

Verification builds trust

Authenticity can be made visible, and that pays off. According to the Spiegel Research Center, a “Verified Buyer” label increases the likelihood of purchase by 15 percent. The mix matters too: A profile with mostly positive and some critical voices appears more credible than one filled with nothing but perfect five-star reviews.

Checklist: How businesses can use reviews effectively

The studies point to ten concrete steps that every business can take to strengthen its review profile:

1. Create and check profiles. Be present on Google and on the platforms relevant to your industry, with correct opening hours, contact details, and links.

2. Actively ask for reviews. Ask every customer after a purchase, appointment, or service visit—preferably by email, SMS, or QR code.

3. Choose the right moment. Send the request shortly after the positive experience, while the memory is still fresh.

4. Collect continuously. Seventy-four percent look only at reviews from the past three months. A steady flow beats a one-off campaign.

5. Aim for the 20-review mark. Almost one in two people avoid businesses with fewer than 20 reviews.

6. Respond to every review. Respond to positive and negative reviews alike, within a few days.

7. Write personally. Avoid copy-and-paste platitudes. AI suggestions are helpful when a human reviews and adapts them.

8. Treat criticism as an opportunity. Respond objectively, offer a solution, and address the problem internally.

9. Maintain multiple platforms. Customers use six platforms on average, not just Google.

10. Play fair. Do not buy reviews, offer incentives for positive reviews, or select only satisfied customers.

It is also worth looking at your own website. More than half of the readers of positive reviews visit it next. Embedding genuine, verified reviews directly on the website reinforces the impression there.

Conclusion: Reviews are no longer a sideshow

Online reviews now help determine who wins the contract, booking, or sale. Almost all consumers read them, and expectations are rising: more stars, more reviews, more recent reviews, and fast, personal responses.

At the same time, a large proportion of businesses make little use of this potential. In Germany, only just under half of SMEs receive reviews at all, and many customers have never received a response. That is precisely where the opportunity lies: Businesses that systematically ask for reviews and respond to every one stand out clearly from the competition.

With the rise of AI-powered search, their importance is growing further. Reviews are no longer just something customers read. They are also what AI systems use to build their recommendations.

About the figures and sources

The most recent surveys come predominantly from the United States, especially BrightLocal’s Local Consumer Review Survey 2026, with 1,002 respondents. German studies are generally several years older (from 2019 to around 2022), but show the same direction. Some sources come from providers of review software. The Birdeye figures are based on data from Birdeye customers and are not representative of all businesses.

• BrightLocal – Local Consumer Review Survey 2026 (US, n = 1,002, February 2026)

• BrightLocal – Local Consumer Review Survey 2020 (US, 2020)

• Bitkom – Online reviews are the most important source of information (Germany, representative, n = 1,103, 2020)

• Spiegel Research Center, Northwestern University – How Online Reviews Influence Sales (US, purchasing data, 2017)

• Michael Luca, Harvard Business School – Reviews, Reputation, and Revenue: The Case of Yelp.com (US, data from 2003–2009)

• PowerReviews Consumer Survey 2025, via Retail Brew (US, 2025)

• Birdeye – State of Online Reviews 2026 (US, customer data, reporting year 2025)

• Capterra – Online reviews among German SMEs, via marketing-boerse.de (Germany, approx. 2022)

• Capterra – Study on the importance of online reviews, via it-daily.net (Germany, n = 685, 2020)

• Capterra, via Deutsches Handwerksblatt (Germany, year not specified)

• GfK commissioned by Greven Medien, via Tageskarte (Germany, representative, 2019)

• Bertelsmann Foundation, Weisse Liste – Doctor reviews (Germany)

• Research Now commissioned by jameda, via Ärzte Zeitung (Germany, n = 1,002)

• Re:spondelligent – Gastro-Webreview Germany 2024, via hogapage (Germany, more than 2,800 restaurants)

• Federal Cartel Office – Sector inquiry into user reviews, via Fieldfisher (Germany, 2020)