diegosouzapw Amazon Category Research
Select the right 3 Amazon categories for your book. This is a one-time, high-stakes decision—categories can't easily be changed after publishing, and 27% of KDP categories are "ghost categories" that don't actually work.
Purpose
Answer one question: Which 3 categories should this book be in?
This skill does NOT cover keywords (separate skill) or book descriptions (separate skill). Just categories.
When to Use This Skill
- "Which categories should I choose for my book?"
- "I'm publishing on KDP and need to pick categories"
- "Is [category name] a good category?"
- "How do I become a bestseller on Amazon?"
- "What categories are my competitors in?"
Not for: Keyword research, book description writing, cover design, or pricing strategy.
The 4-Step Method
Step 1: Find Comp Titles
Identify 5-10 books similar to yours that are selling well.
How to find them:
- Search Amazon for your topic
- Look for books with 50+ reviews and BSR under 100,000
- Note the ASIN (10-character ID starting with B) for each
What makes a good comp:
- Similar topic/genre to your book
- Published in last 2-3 years
- Actively selling (BSR under 100,000)
Step 2: Extract Their Categories
Use BKLNK (free tool) to see all categories for each comp title.
Process:
- Go to bklnk.com
- Enter the ASIN
- See all categories the book is listed in
- Note which categories appear across multiple comps
What you're looking for:
- Categories that multiple successful comps share
- Specific subcategories (not just "Fiction" or "Non-Fiction")
- Categories that actually have bestseller rankings
Step 3: Analyze BSR for Each Category
For each candidate category, check the competition level.
How to check:
- Go to Amazon's category page
- Note the BSR of the #1 book
- Note the BSR of the #20 book
- Use the BSR calculator:
scripts/bsr_to_sales.py
Competition levels:
| #1 Book BSR | Level | What It Means |
|---|---|---|
| < 500 | Very High | Hard to crack |
| 500-5,000 | High | Needs strong launch |
| 5,000-10,000 | Medium | Achievable |
| 10,000-50,000 | Low | Good opportunity |
| > 50,000 | Very Low | Easy, but low traffic |
Step 4: Apply the Portfolio Strategy
Select 3 categories with different competition levels:
| Slot | Target | Purpose |
|---|---|---|
| 1. Niche | BSR #1 > 10,000 | Easy bestseller badge at launch |
| 2. Mid-range | BSR #1 = 5,000-10,000 | Steady visibility |
| 3. Growth | BSR #1 < 5,000 | Upside if book takes off |
Why this works:
- Slot 1 gives you a quick win (bestseller badge = social proof)
- Slot 2 provides consistent discoverability
- Slot 3 positions you for growth
Critical Warning: Ghost Categories
27% of KDP categories are "ghost categories" that:
- Have no category page on Amazon
- Can't earn bestseller badges
- Provide zero discoverability
Before selecting ANY category:
- Search Amazon for that category
- Click through to verify the page exists
- Confirm books in that category have bestseller badges
If you can't find a real category page: DO NOT SELECT IT.
See references/ghost-categories.md for details on identification.
Tools
| Tool | Cost | Use |
|---|---|---|
| BKLNK | Free | See any book's categories by ASIN |
| Kindlepreneur BSR Calculator | Free | Convert BSR to daily sales |
scripts/bsr_to_sales.py |
Free | Local BSR calculator |
| Publisher Rocket | $199-299 | Automated category research + ghost detection |
| KDSPY | $79 | Browser extension for BSR data |
Reality Check: The Free Path Requires Manual Work
BSR data is not easily scraped. Amazon pages are JavaScript-rendered and don't yield BSR numbers to automated tools.
The free workflow:
- Find comp titles via Amazon search (works)
- Extract categories via BKLNK (works)
- Get BSR numbers → Must visit each Amazon product page manually, scroll to "Product Details," and note the BSR
- Convert BSR to sales via calculator (works)
The paid workflow:
- Publisher Rocket ($199-299 one-time) automates steps 2-4 AND detects ghost categories
- KDSPY ($79 one-time) adds BSR overlay to Amazon pages as you browse
Recommendation: For a single book, the free path is fine (budget 1-2 hours). For multiple books or ongoing publishing, Publisher Rocket pays for itself in time saved.
Quick Reference: Research Template
Copy assets/research-spreadsheet.csv and fill in for your book:
| Category Path | BSR #1 | BSR #20 | Ghost? | Competition | Notes |
|---|---|---|---|---|---|
| [Fill in] |
Example: Applying the Method
Book: A guide to Christian fasting practices
Step 1 - Comp titles:
- "Fasting" by Jentezen Franklin (ASIN: B001ANSS7U)
- "The Fasting Edge" by Jentezen Franklin
- "A Hunger for God" by John Piper
- "Atomic Power of Prayer and Fasting" by Cindy Trimm
Step 2 - Categories extracted via BKLNK:
- Religion & Spirituality > Christian Living > Spiritual Growth
- Religion & Spirituality > Christian Living > Prayer
- Health, Fitness & Dieting > Diets > Fasting
Step 3 - BSR analysis:
- Spiritual Growth: #1 BSR = 3,500 (High competition)
- Prayer: #1 BSR = 8,000 (Medium)
- Fasting (Health): #1 BSR = 15,000 (Low)
Step 4 - Selection:
- Niche: Health > Diets > Fasting (easy badge)
- Mid: Christian Living > Prayer (steady)
- Growth: Christian Living > Spiritual Growth (upside)
Bundled Resources
references/bsr-thresholds.md- What BSR numbers mean for salesreferences/ghost-categories.md- How to identify and avoid ghost categoriesreferences/category-examples.md- 8+ real case studies with resultsscripts/bsr_to_sales.py- Convert BSR to daily sales estimatesassets/research-spreadsheet.csv- Template for tracking research
Common Mistakes
- Selecting broad categories - "Fiction" or "Non-Fiction" = drowning in competition
- Not verifying for ghosts - Trust the KDP dropdown at your peril
- All eggs in one basket - Using all 3 slots on similar categories
- Ignoring comp research - Guessing instead of following proven paths
- Set and forget - Categories that worked last year may be saturated now
Related Skills
- kdp-keyword-optimizer - Optimize the 7 backend keyword slots
- book-description-writer - Write conversion-optimized descriptions
- kdp-launch-checklist - Pre-publish validation
Category selection is a strategic decision. 3 slots, 27% ghosts, permanent choice. Research before you publish.