Experiments, Instruments & Measurement — Kindle Category Opportunity
Competition snapshot for the Science & Math best-seller list, ease-of-entry score 53.5/100.
Category metrics
Score
53.5
Median reviews
110
Weak share (top 20)
45%
Median price
$6.99
Median star rating
4.6
Books scanned
50
Worth writing in?
The Experiments, Instruments & Measurement list shows real reader demand with room left for newcomers: the median book carries 110 reviews, yet 45% of the top 20 still sit under 100 reviews. 1 top-15 books hold fewer than 100 reviews at $0.99–4.99 — classic self-publishing breakout books. Ease-of-entry score 53.5/100.
Breakout books — top 15, under 100 reviews, $0.99–4.99
Best-seller list on Amazon| # | Title | Star | Reviews | Price |
|---|---|---|---|---|
| 1 | The Seven Measures of the World | 4.4 | 33 | $1.99 |
High-frequency phrases in this category's titles
Mine all categoriesHigh-frequency phrases mined from the 50 best-seller titles on this category's list. The ease-of-entry score tells you how winnable the category is; these title phrases tell you which words readers search with — use the two layers together. Frequency is a title statistic, not a search-volume estimate.
| Phrase | Titles | Rank-weighted score |
|---|---|---|
| scientific american | 7 | 178 |
| everything electrical | 3 | 56 |
| test circuits like pro | 2 | 37 |
| electrical how to test | 2 | 22 |
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More Science & Math categories
8 subcategories under this category
| Subcategory | Score | Median reviews |
|---|---|---|
| █████ | 100.0 | 0 |
| █████ | 83.0 | 2 |
| █████ | 81.5 | 11 |
| █████ | 73.5 | 10 |
| █████ | 71.0 | 2.5 |
| █████ | 68.5 | 37 |
| █████ | 67.5 | 10.5 |
| █████ | 60.5 | 65 |
Subcategory names are visible after sign-in — a free account unlocks every subcategory score.
Sign up free to unlockCheck the keywords before you write
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After you publish: why aren't readers buying?
Category research picks the direction; review diagnosis reads the readers. The same platform clusters a book's critical reviews into severity-ranked root causes, each anchored to verbatim quotes — see it applied to a full narrative-history title.
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Research snapshot scanned on Oct 19, 2026. Refreshed periodically — not live tracking.