KDP categories · Top KDP authors
Customary (Legal Theory & Systems, Books): Amazon KDP category data
Amazon Books Best Sellers data for Customary (Legal Theory & Systems, Books), updated Nov 3, 2026: median price $36, median 1 reviews, average rating 4.4 and a KDPTop opportunity score of 23/100 (highly competitive).
| Price range (middle 50%) | $17.47 – $56.79 |
|---|---|
| Average rating | 4.4 |
| New releases (90 days) | 1% |
| Books on the list | 100 |
| Store | Books |
What stands out
- Its median reviews are 1% of the parent category Legal Theory & Systems (174), one of the easier corners under it.
- Its review barrier is lower than in 99% of Books categories: the median best seller has only 1 reviews, so new books can chart with few.
- Only 1% of its best sellers are under 90 days old, fewer than in 97% of Books categories: established titles hold the list.
Top 10 Customary best sellers
-
William Blackstone's Commentaries on the Laws of England: Modernized and Condensed: Book I, II, III, and IV
by William Blackstone
- List rank#1
- Price$16.95
- Rating4.6
- Reviews3
-
Spanish English Legal Interpreter Training Manual: Spanish English Criminal Justice, Police, Forensic Science & Courtroom Procedures and Scenarios
by Samuel Arcelay
- List rank#2
- Price$24.99
- Rating5.0
- Reviews4
-
Why Honor Matters
by Tamler Sommers
- List rank#3
- Price$1.99
- Rating4.4
- Reviews100
-
Pirate Money: Discovering the Founders’ Hidden Plan for Economic Justice and Defeating the Great Reset
by Kevin D. Freeman
- List rank#4
- Price$13.19
- Rating4.7
- Reviews291
-
PELLET B Study Guide 2025-2026: All in One UPDATED PELLET B Exam Book 2025 With PELLET B Test Prep 2025 California Material and over 500+ PELLET B Practice Test Questions and Answer Explanations
by David Billrow
- List rank#5
- Price-
- Rating4.2
- Reviews15
-
Duty to Deliberate: Justice by Chance or by Design?
by Kausalya Hegde
- List rank#6
- Price$16.99
- Rating5.0
- Reviews4
-
LSAT Prep Book 2025-2026: 60 Full-Length Practice Tests & New Digital Format | Law School Admission Study Plan | Master Logical & Analytical Reasoning, Reading Strategies for 170+ Score in 28 Days
by Grant Foster
- List rank#7
- Price-
- Rating2.3
- Reviews20
-
U.S. Constitution | Bill of Rights | Declaration of Independence |: - Large Print | Founding Documents of the United States | Unabridged New Edition
- List rank#8
- Price$8.20
- Rating4.8
- Reviews11,644
-
Legal Traditions of the World: Sustainable Diversity In Law
by H. Patrick Glenn
- List rank#9
- Price$72.57
- Rating4.3
- Reviews43
-
Legal Bloopers and Blunders Adult Trivia Book: A Worldwide Collection of Hilarioius and Peculiar Lawsuits
by B N William
- List rank#10
- Price$12.99
- Rating3.9
- Reviews14
FAQ
Is Customary a good niche for Amazon KDP?
Its KDPTop opportunity score is 23/100, which makes it highly competitive. The median best seller has 1 reviews and sells for $36.
How many reviews do you need to rank in Customary?
The median best seller has 1 reviews, and 99% of them have fewer than 100.
What do Customary best sellers cost?
The median price is $36; half of the best sellers are priced between $17.47 and $56.79.
Can new books break into Customary?
1% of the current best sellers were released in the last 90 days.
About this data
Data comes from KDPTop's daily crawl of Amazon's public Best Sellers pages; medians use the latest list. The opportunity score (0–100, higher is easier to enter) combines the review barrier, the share of low-review books, list turnover, new-release share and price.