What KDP keywords actually do
KDP gives you seven keyword slots in the back end of your book listing. Each can hold a phrase up to 50 characters. They do two things:
- Tell Amazon which search results to show your book in (e.g. someone types "small town romance Christmas" — Amazon checks who matches).
- Unlock hidden categories that aren't visible in the public dropdown when you publish.
That's it. They don't show on the public page. They are not meta-tags. They are search inputs.
The big mistake
90% of authors fill the slots with words like fiction, novel, bestseller, paperback, kindle, ebook, book. Every one of those is wasted. Amazon already knows your book is a kindle ebook fiction novel — you don't need to tell it. Use the slots for things only you know about your book.
Step 1: Find what real readers search
Open Amazon. Make sure you're in the Books or Kindle store. Start typing the kind of phrase your ideal reader would search. Amazon's autocomplete is the most valuable free keyword research tool in publishing — every suggestion is a real search people have actually run.
Try patterns like:
- cosy mystery [setting] → cosy mystery English village
- [main feeling] romance → enemies to lovers romance
- [topic] for [audience] → ADHD productivity for women
- books like [comp title] → books like Verity
Write down 30–40 phrases. Don't filter yet.
Step 2: Score them by reader-fit
For each phrase ask: if a reader who typed this found my book, would they buy it? Be honest. A phrase with huge volume but the wrong audience is worse than a small phrase with the perfect audience — because mismatched clicks tank your conversion rate, which Amazon's algorithm reads as "this book isn't great" and shows you less.
Cut the phrases where the answer is "maybe." Keep the strong yeses.
Step 3: Pack the seven slots
Each slot holds 50 characters and Amazon matches every individual word inside it. So "slow burn enemies to lovers small town romance"in one slot covers slow burn, enemies to lovers, small town romance, slow burn romance, small town enemies, etc. Pack phrases, not single words.
A workable structure:
- Genre + sub-genre phrase
- Tropes you actually deliver
- Setting / time period
- Reader feeling (heart-warming, dark, fast-paced)
- Comp-author or "books like X" phrase
- Audience qualifier (for women, for teens, for new managers)
- Long-tail bonus phrase
What to never put in the slots
- Other authors' names. Amazon will pull your book.
- Other book titles you didn't write.
- Trademarked terms ("Tony Robbins method").
- "Free", "bestseller", "award-winning" — Amazon ignores or penalises these.
- Quotation marks or punctuation. Plain words separated by commas only.
Step 4: Update and wait
Save the changes in KDP. New keywords take 24–72 hours to flow through Amazon's index. Don't change them again for at least two weeks — the algorithm needs time to re-rank you.
The shortcut
If you'd rather not spend a Saturday afternoon doing this manually, the Book Discoverability Score scans your live listing and proposes seven ready-to-paste KDP keywords based on what real readers in your sub-genre actually search. Free, 60 seconds, no signup.