What’s your star rating costing you?

Northwestern University’s Spiegel Research Center measured how star ratings change the odds a shopper actually buys. Enter your numbers below and see what moving your rating is worth — and how long it takes to get there.

270%Higher purchase likelihood, 5 reviews vs. none
380%Conversion lift for high-priced purchases
4.24.5The conversion sweet spot

Your numbers

Run your own numbers

Three inputs. Then drag the target and watch what a better rating does to the cost of the leads you’re already buying.

Where shoppers research you
Or monthly traffic you pay for
$
Blended across channels
4.4★
Sweet spot
1★2★3★4★5★
Fine-tune (optional)
Turns the lift into customers per year
Used for the timeline projection below
Annual lead spend saved at the same volume of customers
More conversions from the same spend
Purchase-likelihood multiplier

Savings assume conversion scales with the Spiegel purchase-likelihood curve below: at a higher rating you need fewer paid leads for the same customers, or get more customers from the same spend.

The research

More stars, more sales — up to a point

Across five product categories, Northwestern found purchase likelihood climbs steeply with star rating, peaks between 4.2 and 4.5 stars, then falls as ratings approach a perfect 5.0. Shoppers read near-perfect scores as too good to be true — 82% of them seek out negative reviews on purpose.

Relative purchase likelihood by average star rating, from the Spiegel Research Center’s findings (peak normalized to 1.0). The red dot is your rating today; the green diamond is your target.

Why this matters more for you: the effect is strongest exactly where decisions are hard — expensive, risky, or unfamiliar purchases. Displaying reviews lifted conversion 190% for low-priced items and 380% for high-priced ones in the same categories.

How you get there

The path from your rating to your target

A rating doesn’t move because you wish it up — it moves when verified, recent reviews out-weigh old ones. ConsumerAffairs reaches your real customers by phone, email and brand review forms; the average collection program brings in roughly 19 verified reviews a month, averaging about 4.5★ (May 2026 average across ~300 active programs). Here’s your timeline on that pace, using ConsumerAffairs’ published 24-month weighted rating method.

Months to your target
Verified reviews needed
Reviews collected per month

Your projected displayed rating, month by month, computed with ConsumerAffairs’ time- and verification-weighted 24-month method. Recent verified reviews count most; old reviews age out of the window.

ConsumerAffairs’ published method: “A company’s ratings are a time-based and verification-based weighted average numerical calculation of the ratings submitted by consumers in the most recent 24-month period.”

Recent reviews count far more than old ones — which is why proactive collection moves the number fast, and why last year’s negatives quietly lose their grip.

Proof it works

A brand that already made this climb

Patio Enclosures spent a year at a single star — organic reviews only, mostly unhappy voices. When ConsumerAffairs started collecting verified reviews from their real customers, the math above played out in public.

1.1 → 4.1Displayed star rating
~2 mo.To clear 3.5 stars
4.6Avg. verified review

The rating crossed 3.5 in the first month plus of collection and topped 4.0 within roughly four — and as of June 2026 the brand ranks in Google’s AI Overview for its category search.

“I am pleasantly surprised in how quickly we were able to get our rating turned around on the ConsumerAffairs platform — getting us from a 1.0 rating to where we are now is a testament to their process & methodology. To say I’m thrilled with the results is an understatement.”

— Melissa Skinner, VP of Marketing, Patio Enclosures

See this with your real review data

Your inputs are saved in this page’s link — copy it and send it back to us, or book a call and we’ll model your exact path with your category, your review history, and your lead economics.