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System Theory (Physics, Kindle eBooks): Amazon KDP category data
Amazon Kindle eBooks Best Sellers data for System Theory (Physics, Kindle eBooks), updated Nov 3, 2026: median price $9.95, median 19 reviews, average rating 4.3 and a KDPTop opportunity score of 22/100 (highly competitive).
| Price range (middle 50%) | $5.83 – $15.49 |
|---|---|
| Average rating | 4.3 |
| New releases (90 days) | 8% |
| Books on the list | 100 |
| Store | Kindle eBooks |
What stands out
- Its median reviews are 3% of the parent category Physics (682), one of the easier corners under it.
- The same niche in Books scores 34, 12 points higher than here; worth checking both.
- Its review barrier is lower than in 73% of Kindle eBooks categories: the median best seller has only 19 reviews, so new books can chart with few.
Top 10 System Theory best sellers
-
Black Holes: The Key to Understanding the Universe
by Brian Cox
- List rank#1
- Price$1.99
- Rating4.6
- Reviews1,581
-
Thinking in Systems: International Bestseller
- List rank#2
- Price$16.99
- Rating4.6
- Reviews6,548
-
Scientific American September 2026
- List rank#3
- Price$6.99
- Rating4.8
- Reviews13
-
Scientific American October 2026
- List rank#4
- Price$6.99
- Rating4.2
- Reviews7
-
Scientific American June 2026
- List rank#5
- Price$6.99
- Rating4.4
- Reviews42
-
Scientific American November 2026
- List rank#6
- Price$6.99
- Reviews-
-
-
The Entropy Trap: What Physics Knows that Markets Don't
by Mickey M Maini
- List rank#8
- Price$9.99
- Rating4.7
- Reviews82
-
Scientific American July/August 2026
- List rank#9
- Price$6.99
- Rating4.7
- Reviews8
-
Systems 1: An Introduction to Systems Thinking
by Draper Kauffman
- List rank#10
- Price$4.99
- Rating4.3
- Reviews70
Same niche in Books: System Theory
FAQ
Is System Theory a good niche for Amazon KDP?
Its KDPTop opportunity score is 22/100, which makes it highly competitive. The median best seller has 19 reviews and sells for $9.95.
How many reviews do you need to rank in System Theory?
The median best seller has 19 reviews, and 68% of them have fewer than 100.
What do System Theory best sellers cost?
The median price is $9.95; half of the best sellers are priced between $5.83 and $15.49.
Can new books break into System Theory?
8% 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.