A go, maybe or no-go from the search page you have open
Search for a product on Amazon and Shelfverdict stamps the page. Five checks on the top ten organic results, each shown with its limit, and a plain sentence on what failed. It reads what is already on your screen and fetches nothing.
Free, no account, no cap on verdicts.
Five checks, each with its limit written down
The limits are beginner rules of thumb, not law. Two are our own, and the sheet says which.
| Check | What it counts | Passes when | Where the limit comes from |
|---|---|---|---|
| Review barrier | Median reviews of the top 10 organic results | 500 or fewer | Rule of thumb: top-10 average under 500 reviews, read here as the median so one giant listing does not hide a thin niche. |
| Young listings | Top 10 listings with under 100 reviews | 3 or more | Rule of thumb: several listings under 100 reviews that still sell, read here as at least 3 of 10. |
| Ad share | Sponsored cards among all cards on the page | 30% or less | Our own limit; no published figure. |
| Brand hold | Share of the top 10 held by the top brand, guessed from the first word of each title | 30% or less | Rule of thumb: no dominant brand. The 30% figure is ours. |
| Price band | Median price of the top 10 | $15 to $50 €15 to €50 £12 to £40 | Rule of thumb: price $15 to $50. The euro band keeps the numbers; the pound band is set lower by us. |
No check fails
GoAll five pass, or all that could be judged.
One check fails
MaybeThe summary names the check that failed.
Two or more fail
No-goThe niche fails on more than one count.
A check it cannot judge counts neither way. A page in a currency with no band, or with mixed currencies, is not judged on price. With fewer than five organic results the page says “No verdict” and shows no stamp.
When two neighbouring prices in the top ten differ by more than 40%, the card also says so, for example that no listing sits between $14.00 and $25.00. That line is information and is not scored.
Reading a verdict and what each check means go through the sheet line by line.
Every result tagged with where it ranks
Each card on the page gets a small tag under its stars.
The tag says sponsored, or organic with its rank. The review count sits beside a bar on a log scale from 0 to 100,000 reviews, with ticks at 100 and 500. A listing under 100 reviews gets a moss bar and counts as a young listing in the verdict.
Example rows, invented data.
Bamboo cutting board with juice groove, extra large
sponsored8,420 reviewsOrganic bamboo chopping board set of 3
organic #12,310 reviewsKitchen cutting board, bamboo, with handle
organic #2641 reviewsWooden cutting board for meat and cheese
organic #3187 reviewsBamboo chopping block, 12 inch
organic #464 reviews, under 100Small bamboo board for bar and prep
organic #523 reviews, under 100
Fee and margin sheet
Worked out on your computer. Nothing you type is kept or sent.
Enter a price and what a unit costs you. The sheet takes Amazon’s referral fee from a dated table and shows profit per unit, margin and return on unit cost. The FBA fulfilment fee depends on size and weight and we could not confirm a fee table for it, so you type it from Amazon’s own calculator.
Worked example, invented numbers
- Selling price
- $24.00
- Referral fee, 15%
- −$3.60
- Fulfilment fee (you type it)
- −$5.50
- Unit cost (you type it)
- −$6.00
- Other per unit (ads, storage, returns)
- −$2.00
- Profit per unit
- $6.90
- Margin on price
- 29%
- Return on unit cost
- 115%
| Storefront and category | Referral | Per item at least |
|---|---|---|
| amazon.com, Home & Kitchen | 15% | $0.30 |
| amazon.com, Sports & Outdoors | 15% | $0.30 |
| amazon.com, Pet Supplies (not veterinary diets) | 15% | $0.30 |
| amazon.it, Cucina | 15% | €0.30 |
Rows read from Amazon’s own fee pages on 2026-10-05, which carry no date of their own. Only confirmed rows are listed. For any other category or storefront you type the percentage from Seller Central.
Free and Pro
Free is a working tool with no cap on verdicts. Pro adds memory.
Free
€0
- The verdict and its five checks on every search page
- A tag on every result: organic rank or sponsored, with a review bar
- Product readout: rank as printed, price, reviews, fulfilment, offers
- The fee and margin sheet
- Every storefront it reads, no cap
- No history, no saved niches, no CSV
Pro
€39 a year or €79 once
- Everything in Free
- Rank, price and review history of each product you open, kept on your computer, with review growth
- Saved niches, with the products you pick in them
- The competitor table of a search as a CSV file
- 7 days of Pro to try, no card
Buy for life, €79 Buy a year, €39
One payment, nothing renews. How buying works
What it cannot tell you
No sales numbers
Best Sellers Rank is shown as the page prints it. Shelfverdict does not turn a rank into units sold or revenue, because that would be a guess.
Brands are a guess
The brand is guessed from the first word of each title. The card marks that check as an estimate.
Five results or no verdict
A page with fewer than five organic results says too little. It shows the cards it found and says why there is no stamp.
Only the page you opened
It reads the search or product page in your tab. It does not crawl, schedule or look at other pages for you.
Six storefronts
The extension holds access to these six and no other website. Its page reader is tested on saved search and product pages from amazon.com and amazon.it.
- amazon.comPrice band in dollars
- amazon.co.ukPrice band in pounds
- amazon.dePrice band in euros
- amazon.itPrice band in euros
- amazon.frPrice band in euros
- amazon.esPrice band in euros
Questions
Where do my searches go?
Nowhere. The page is read in your browser and what is kept stays in the extension’s own storage. Two things can leave your computer, and only when you ask: a licence key when you activate Pro, and a suggestion when you press Send. The privacy policy lists both.
Does it fetch Amazon pages itself?
No. It reads the search or product page you already opened and never requests an Amazon page on its own.
Is that allowed under Amazon’s terms?
Amazon’s Conditions of Use, updated 5 May 2026 and read through a third-party summary, forbid data mining, robots and similar data gathering tools. Shelfverdict gathers nothing by itself and only reads the page in front of you, but whether that falls under the terms has not been tested. We found no action against comparable overlays. You decide whether to use it.
Why did I get a maybe?
One check failed. The summary under the stamp names it, and the guide to reading a verdict says what each case usually means.
What happens when the trial or a pass ends?
What is saved stays on your computer. Only the Pro features switch off, and they come back with a pass.
Does it work on Firefox and Edge?
It is built for Chrome, Edge and Firefox. The store buttons on this page link to each listing as it goes live.
How is it different from Helium 10 or Jungle Scout?
Those are subscription suites built around sales estimates. Shelfverdict gives one explained verdict and plans a one-time pass. The comparison marks which figures are reported.