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How Much Reviews Affect Whether Customers Call You
Two well-known studies of restaurants put a number on what a better rating is worth, and the same arithmetic lets any service business estimate what half a star means in its own revenue.
At a glance
- An extra half-star on Yelp made San Francisco restaurants 19 percentage points more likely to sell out their reservations, a 49% increase, in research published in the Economic Journal.
- A Harvard Business School study of restaurants in Washington State found that a one-star increase in Yelp rating led to a 5% to 9% increase in revenue, with the effect concentrated in independent restaurants rather than chains.
- For an illustrative business with $350,000 in yearly revenue, a half-star improvement is worth roughly $8,750 to $15,750 a year if the restaurant findings hold.
The number and where it comes from
The owner's inner voice about reviews often runs People call us because they know us, not because of a few stars online, and for long-standing regulars that may be true, but the first-time customer who has never met anyone at the business is reading the same rating everyone else reads. The cleanest evidence on what that rating does comes from a feature of Yelp's display: the site rounds each restaurant's average to the nearest half-star, so two restaurants with nearly identical averages, say 3.74 and 3.76, show different stars.
Researchers at the University of California, Berkeley used that rounding as a natural experiment, comparing restaurants just above and just below each cutoff in a sample of 3,953 San Francisco restaurants, with reservation data for 328 of them. They found that "an extra half-star rating causes restaurants to sell out 19 percentage points (49%) more frequently," with larger effects when other information about a restaurant was scarce.
A separate study from Harvard Business School matched Yelp ratings with restaurant revenue data from the Washington State Department of Revenue and found that a one-star increase led to a 5% to 9% increase in revenue. The effect was driven by independent restaurants, while chains showed none, and together with the Berkeley finding that ratings mattered most where other information was scarce, that points to owner-run businesses with no national brand to lean on as the ones whose ratings carry the most weight.
Customers also screen on rating and volume before they call. In BrightLocal's 2026 survey of 1,002 U.S. adults, run by a local search software company, most respondents set a floor below which they would not consider a business at all.
Perfect is not the target, though. Research from Northwestern University's Spiegel Research Center, based on online retail data, found that purchase likelihood typically peaks for ratings between 4.0 and 4.7 and declines as ratings approach 5.0, so a few honest four-star reviews among the fives do no harm.
The calculation
The restaurant findings can be turned into a rough estimate for any business: annual revenue × revenue effect per star × change in rating. The result is a range, because the research gives a range, and it assumes that half a star is worth about half of a full star.
| Input | Low | High | Source |
|---|---|---|---|
| Annual revenue | $350,000 | $350,000 | Assumption |
| Revenue effect of one full star | 5% | 9% | Harvard Business School study of Washington State restaurants |
| Rating change | +0.5 | +0.5 | Assumption |
| Effect scales in proportion to the change | Yes | Yes | Assumption |
| Revenue effect of the change | 2.5% | 4.5% | Calculated (5% or 9% × 0.5) |
| Added revenue per year | $8,750 | $15,750 | Calculated ($350,000 × 2.5% or 4.5%) |
How you compare
- Rating: if your Google rating is below 4.0, you are under the floor that 68% of consumers in the BrightLocal survey say they use, and every review request you send matters more.
- Count: if you have fewer than 20 reviews, nearly half of surveyed consumers say they would pass you over.
- Practices: in an older JAMA survey of 2,137 U.S. adults, fielded in 2012, 35% of people who had looked up physician ratings in the past year said they chose a physician because of good ratings, and 37% said they avoided one because of bad ratings.
- Your own baseline: write down your rating, review count and reviews received in the last 90 days, then ask new callers whether they read your reviews before calling.
Sources
- Anderson, M. and Magruder, J. Learning from the Crowd: Regression Discontinuity Estimates of the Effects of an Online Review Database. Economic Journal 122(563), 2012. 3,953 San Francisco restaurants; reservation data for 328.
- Luca, M. Reviews, Reputation, and Revenue: The Case of Yelp.com. Harvard Business School Working Paper 12-016, revised 2016. Restaurant revenue data from the Washington State Department of Revenue.
- BrightLocal. Local Consumer Review Survey 2026. 2026. Panel of 1,002 U.S. adults.
- Spiegel Research Center, Northwestern University. How Online Reviews Influence Sales. First published 2017.
- Hanauer, D. A., Zheng, K., Singer, D. C., Gebremariam, A. and Davis, M. M. Public Awareness, Perception, and Use of Online Physician Rating Sites. JAMA 311(7), 2014. 2,137 U.S. adults.
Related reading: How to Get More Reviews Without Begging, Based on What Makes Customers Write Them · The Review Request Text to Send After Every Visit · What Customers Learn About Your Business Before They Ever Call · The No-Beg Way to Stack Up 5-Star Reviews This Month (free live session)
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