KDP categories · Top KDP authors
John Walker: Amazon KDP author data
John Walker has 125 books on Amazon, 35 of them on a best-seller list in the last 30 days (best rank #1), mostly in Colonization, Galactic Empire, Genetic Engineering.
125Books on Amazon
35Listed in 30 days
4.4Average rating
| Median price | $4.99 |
|---|---|
| Price range (middle 50%) | $0.99 – $4.99 |
| Median reviews | 814 |
| Total reviews | 131,566 |
| New books (30 days) | 17 |
| Breakout books (30 days) | 14 |
What stands out
- 17 new books in the last 30 days, 14 of them broke into a Best Sellers list.
John Walker's best-ranked books
-
Starship Express
by John Walker
- Price$0.99
- Rating4.4
- Reviews1,551
- Published2026-08
-
First Explorer
by John Walker
- Price$0.99
- Rating4.3
- Reviews70
- Published2026-10
-
Unexpected Visitor
by John Walker
- Price$0.99
- Rating4.3
- Reviews12
- Published2026-10
-
Fowarding Address (Starship Express Book 2)
by John Walker
- Price$4.99
- Rating4.5
- Reviews459
-
Unwanted Starship
by John Walker
- Price$0.99
- Rating4.4
- Reviews5,595
-
-
-
-
Spacebar: The Complete Series
by John Walker
- Price$0.99
- Rating4.4
- Reviews448
-
Somebody's Home (Unwanted Starship Book 6)
by John Walker
- Price$4.99
- Rating4.5
- Reviews57
Main categories
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.