KDP categories · Top KDP authors
John Maddox Roberts: Amazon KDP author data
As of Nov 6, 2026, John Maddox Roberts has 14 books on Amazon, 12 of them on a best-seller list in the last 30 days (best rank #3), mostly in Ancient, Historical, Private Investigators.
| Median price | $11.02 |
|---|---|
| Price range (middle 50%) | $10.14 – $16.49 |
| Median reviews | 258 |
| Total reviews | 3,630 |
| New books (30 days) | 0 |
| Breakout books (30 days) | 0 |
What stands out
- 86% of the catalog made a best-seller list in the last 30 days: the whole backlist sells, not one hit.
- Median price $11.02, 19% below the median of their main category, Ancient.
John Maddox Roberts's best-ranked books
-
SPQR I: The King's Gambit: The Kings Gambit (The SPQR Roman Mysteries Book 1)
by John Maddox Roberts
- Price$9.21
- Rating4.4
- Reviews507
-
SPQR XI: Under Vesuvius: A Mystery (The SPQR Roman Mysteries Book 11)
by John Maddox Roberts
- Price$10.08
- Rating4.5
- Reviews260
-
SPQR III: The Sacrilege: A Mystery (The SPQR Roman Mysteries Book 3)
by John Maddox Roberts
- Price$8.96
- Rating4.4
- Reviews301
-
SPQR VII: The Tribune's Curse (The SPQR Roman Mysteries Book 7)
by John Maddox Roberts
- Price$19
- Rating4.6
- Reviews255
-
SPQR IV: The Temple of the Muses (The SPQR Roman Mysteries Book 4)
by John Maddox Roberts
- Price$10.63
- Rating4.3
- Reviews249
-
SPQR II: The Catiline Conspiracy
by John Maddox Roberts
- Price$14.99
- Rating4.2
- Reviews289
-
SPQR X: A Point of Law: A Mystery (The SPQR Roman Mysteries Book 10)
by John Maddox Roberts
- Price$17.91
- Rating4.5
- Reviews217
-
SPQR VI: Nobody Loves a Centurion
by John Maddox Roberts
- Price$11.19
- Rating4.5
- Reviews287
-
SPQR IX: The Princess and the Pirates: A Mystery
by John Maddox Roberts
- Price$2.99
- Rating4.4
- Reviews244
-
SPQR VIII: The River God's Vengeance (The SPQR Roman Mysteries Book 8)
by John Maddox Roberts
- Price$11.52
- Rating4.5
- Reviews279
Main categories
FAQ
How many books does John Maddox Roberts have on Amazon?
KDPTop tracks 14 of their books; 12 made an Amazon list in the last 30 days.
Which categories does John Maddox Roberts publish in?
Their books chart most often in Ancient, Historical, Private Investigators.
How does John Maddox Roberts price their books?
The median price is $11.02; half of the books cost $10.14–$16.49.
Has John Maddox Roberts released new books recently?
0 new books in the last 30 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.