Why did a business's score drop when it got a new positive review?

It almost never does from a positive review alone. More likely an older high-rated review crossed another 90-day half-life at the same time, or a flagged review was resolved. The nightly recompute applies both. Scores under 10,000 reviews also update in real time when a review is published.

Does paying RooVello improve a score or ranking?

No. Score and rank are computed from reviews only. The billing table is not read by any public page or API, and a test asserts this on every deploy. The only paid tool sends review requests to a business's own customers, and the resulting reviews are labeled as invited.

What is review-bombing protection?

If a business receives more reviews in 48 hours than in the previous 30 days, new reviews are held out of the score for seven days while they are checked. They stay visible with their labels, so readers can see what is happening.

Where can I see the formula applied to a real profile?

Every profile links to a markdown version (add .md to the URL) that lists the counted reviews, their labels and dates, and the computed scores. The home page has an interactive version of the formula.

Guides · For readers

How review scores are calculated on RooVello

Updated November 13, 2026 · markdown

RooVello scores are a weighted Bayesian average: every business starts with seven imaginary reviews at 3.5, each real review's weight halves every 90 days, verified reviews count fully, unverified at 60 percent, imported at 40 percent, and insiders not at all. The result is a score that a handful of extreme reviews cannot swing and that reflects how a business is doing now, not in 2019.

The formula

score = (7 × 3.5 + Σ wᵢ × ratingᵢ) / (7 + Σ wᵢ), where wᵢ = 2^(−age_daysᵢ / 90) × label_weightᵢ.

In words: add seven reviews of 3.5 to the real ones, weight each real review by how recent it is and how it was collected, and take the weighted average. Age is measured from the service date when the reviewer gives one, otherwise from the posting date.

Why the prior matters

Without the prior, one five-star review makes a business a 5.0 and one angry review makes it a 1.0. With seven imaginary reviews at 3.5, a single 5-star review moves a new business to about 3.7, and it takes a consistent run of good reviews to reach 4.5 or above. The prior fades as real reviews accumulate: at a few dozen recent reviews it barely matters.

This is also why a 4.9 from four reviews can rank below a 4.6 from four hundred. The second business has earned its score; the first has not yet.

Why recent reviews weigh more

A review from three years ago describes a business that may have changed owners, crews or policies twice. Halving the weight every 90 days means a review from a year ago counts about 6 percent of a review from today. Old reviews never disappear; they just stop steering the number.

Label weights

Each review's weight is also multiplied by how it was collected and whether the customer was verified.

Verified customer: 1.0
Unverified: 0.6
Invited by the business with an incentive disclosed: 0.8
Imported by the business from its own Feefo, Google or Yelp export: 0.4, and never in the verified-only score
Insider (reviewer on the business's own email domain): 0, excluded
Under an unresolved flag: 0 until a moderator decides

Two scores, labels and ranking

The verified-only score uses the same formula but only verified reviews. Scores are rounded to one decimal and labeled: 1.0 to 1.7 Bad, 1.8 to 2.7 Poor, 2.8 to 3.7 Average, 3.8 to 4.2 Great, 4.3 to 5.0 Excellent. A business with fewer than three counted reviews shows "Not enough reviews".

Lists rank by score, then review count, then name. Nothing a business can buy enters the calculation; that is enforced in code and in an automated test that runs on every build.

Frequently asked

Why did a business's score drop when it got a new positive review?: It almost never does from a positive review alone. More likely an older high-rated review crossed another 90-day half-life at the same time, or a flagged review was resolved. The nightly recompute applies both. Scores under 10,000 reviews also update in real time when a review is published.
Does paying RooVello improve a score or ranking?: No. Score and rank are computed from reviews only. The billing table is not read by any public page or API, and a test asserts this on every deploy. The only paid tool sends review requests to a business's own customers, and the resulting reviews are labeled as invited.
What is review-bombing protection?: If a business receives more reviews in 48 hours than in the previous 30 days, new reviews are held out of the score for seven days while they are checked. They stay visible with their labels, so readers can see what is happening.
Where can I see the formula applied to a real profile?: Every profile links to a markdown version (add .md to the URL) that lists the counted reviews, their labels and dates, and the computed scores. The home page has an interactive version of the formula.

About this guide

Written by the RooVello team and kept current with the platform's actual rules; every statement about how RooVello works describes code that runs on this site. Statements about other platforms restate their public pricing and policy pages and should be confirmed there. Nothing here is legal advice.