Category research is what separates authors who rank from authors who disappear. Here’s the step-by-step process for identifying categories that are real, relevant, and reachable for your specific book.
| 9-minute read | All levels |
Most authors pick categories during book upload by scrolling through KDP’s dropdown and selecting whatever looks vaguely right. Some spend ten minutes; many spend two. The result is category placement that’s often inaccurate, sometimes in ghost categories, and rarely optimised for the competition level the author can actually beat. Good category research takes longer — 30 to 60 minutes the first time you do it properly — but the payoff is months of improved organic visibility.
This guide walks through the complete category research process: identifying candidate categories, evaluating each one for competition level, checking whether it’s real or a ghost, and arriving at a final shortlist of three placements that give your book the best chance of ranking visibly and earning a bestseller badge.
Step 1: Build a Candidate List
Start by generating a list of 10–15 category paths that could plausibly fit your book. Don’t filter yet — this is a brainstorming stage. For fiction, think about your genre, subgenre, protagonist type, setting period, and any specific niche identifiers (cozy mysteries with animals, small-town romance, grimdark fantasy). Each of these dimensions points toward a different category in the KDP hierarchy. For nonfiction, consider your subject domain, target audience, and specific topic — a book about productivity for remote workers might qualify for Business Productivity, Remote Work, Time Management, and Home Office categories.
The fastest way to generate your initial list is to look at five to ten comparable books — books that would sit on the same Amazon shelf as yours if they were in a physical bookshop. Find these by searching Amazon for your book’s core genre or subject, then examining the “Best Sellers Rank” section at the bottom of each book’s product page. Note every category listed there. After examining five to ten comparable books you’ll have a rich initial list of categories that are actively used by books like yours, with no guesswork required.
Also check the KDP category browser directly. In the KDP Bookshelf, edit any book’s details and open the category selection dropdown. Browse the hierarchy from your top-level genre downward, noting every subcategory path that could apply. The browser structure shows you what Amazon considers to be related — sometimes revealing category options that don’t appear in your competitor research because they’re used by books you haven’t discovered yet.
Step 2: Assess Competition in Each Category
For each candidate category, you need two pieces of data: how competitive is the category, and how many sales do you need per day to rank in the top 10–15? Both can be estimated from Amazon’s publicly visible BSR data.
Navigate to a candidate category’s browse page on Amazon (click through from any book already in that category). Find the books ranking in positions 10 through 15 on the main bestseller list. Click each book and note its overall Best Sellers Rank — the sitewide rank shown in the Product Details section, not its category rank. A book with an overall BSR of 50,000 is selling roughly 4–6 copies per day. A book with an overall BSR of 200,000 is selling roughly 1–2 copies per day. A book with an overall BSR of 500,000 may sell only 2–3 copies per week.
The overall BSR of the #10–15 book in a category tells you what sales velocity is required to enter the top of that category. Compare this against your realistic expected daily sales at launch. If you’re expecting 3–5 sales per day from a modest ad campaign, categories where the #10 book has an overall BSR of 100,000–300,000 are in your attainable range. Categories where the #10 book has an overall BSR of 20,000 or lower are probably too competitive to rank in without a significant launch budget or established audience.
Check the Hot New Releases list too. Every category also has a Hot New Releases tab showing books published in the last 30 days. The competition here is almost always lower than the main list, and the sales velocity required to rank in the top 10 is typically 50–70% lower. For a new book, this list can be more important than the main bestseller list in the first month.
Step 3: Verify Categories Are Real, Not Ghost
Before committing any category to your final shortlist, verify it’s a live, browseable category and not a ghost. There are two ways to do this. The manual method: find a book already listed in the candidate category (you can see this on any book’s product page in the “Best Sellers Rank” section). Click the category link on that book’s page. If it takes you to a browseable page with multiple titles listed, sorted by rank, with a bestseller list — it’s real. If it produces an error, an empty page, or the link isn’t clickable, it’s a ghost.
The faster method is to use KDP Rank Fuel’s Category Research tool, which flags ghost categories automatically as you browse the category hierarchy. This saves the manual click-through process for each candidate category, which becomes time-consuming when you’re evaluating 15+ options. The tool also shows current bestseller rank data for each category, combining steps two and three into a single workflow.
If you discover that a category you were planning to use is a ghost, remove it from your shortlist entirely. Don’t place your book there hoping Amazon will eventually populate it — ghost categories offer no visibility, no bestseller rank, and no reader browsing. They are wasted slots regardless of how relevant the category name sounds.
Step 4: Check for Duplicates
Narrow your shortlist to genuine distinct categories. When you open the KDP category selector and choose a category, duplicates of that category will grey out in the interface — this is the partial safeguard built into KDP’s system. However, it’s worth manually checking whether any of your shortlisted categories lead to the same Amazon category page before you’ve made your selection.
To check: find a book in each candidate category and compare the category browse pages. If two category paths from your shortlist take you to the same page with the same bestseller list — even if their names look slightly different — they’re duplicates. Use only one of the duplicate paths and allocate the freed slot to a genuinely different category.
Step 5: Finalise Your Three
With your cleaned, verified shortlist, select three categories that together maximise your book’s discovery coverage. Aim for at minimum: one accurate primary category where your ideal readers browse (even if competitive), one category where you have a realistic path to the top 10–15 in the main bestseller list or top 5 in Hot New Releases, and one category that covers a different dimension of the book’s potential audience.
Record your final selections and the rationale for each. Log the BSR of the #10 book in each category at the time of your research — this is your baseline for tracking whether your placement is competitive over time. When you check your rank in these categories after launch, you can compare your achieved rank against that baseline to assess whether each category choice is working for you.
Automate Your Category Research
KDP Rank Fuel’s Category Research and Category Finder tools do the heavy lifting — identifying live categories, showing competition data, and flagging ghosts and duplicates before you spend a single slot.
Reading Category Browse Pages Like a Pro
Once you’re on a category browse page, there’s more useful data available than just the top-ranked book BSRs. Look at the total number of results shown for the category — Amazon typically displays this as “1–16 of over X results” at the top of the page. A category with 200 total results is a niche category where ranking in the top 10 puts your book in the top 5% of all titles. A category with 50,000 results is a major category where top-10 rank still represents top 0.02% — an impressive achievement, but one requiring sustained sales to maintain.
Also examine the age of books ranking in the top 20. If most of the top-ranking books were published within the last 12 months, the category is active and dynamic — new entrants can rank if they generate enough sales velocity. If the top 10 is dominated by books published three to five years ago with very high review counts, it suggests a more entrenched category where newcomers face a longer climb. Active, dynamic categories are generally more accessible for new books even when their overall BSR requirements are similar to entrenched ones, because the top positions turn over regularly.
The price range of top-ranking books also matters. If all the books in the top 10 of a category are priced at £0.99–£2.99, and your book is priced at £5.99, you may face a conversion rate disadvantage when browsers compare your listing against the competition — even if your ads or organic rank puts you in the same results page. Checking the pricing landscape in your candidate categories helps you anticipate whether your price point is competitive for that specific audience.
Using Review Counts as a Competition Signal
Beyond BSR, review counts on top-ranking books give you a secondary signal of how entrenched the competition is. A category where the top 10 books each have 500–2,000 reviews represents established titles with significant social proof. A new book entering that category will convert at a lower rate than the incumbents even if it achieves a similar rank, because readers comparing titles will weigh the review volume. This doesn’t make the category off-limits, but it’s important context for your conversion rate expectations.
Conversely, a category where top-ranking books have 10–50 reviews is one where reader behaviour isn’t strongly anchored to review volume — either the category is niche enough that readers accept lower review counts, or the category is newer and social proof norms haven’t fully established. New books entering these categories face less of a conversion disadvantage from low initial review counts, making them more accessible for launches that haven’t yet accumulated review volume.
The ideal category profile for a new book launch is one where: the top 10 books have overall BSRs in the 100,000–400,000 range (reachable with modest sales), review counts are below 200 for most top-10 titles (limited social proof advantage for incumbents), the Hot New Releases list shows books published recently with relatively low BSRs (confirming the category is active), and the category is verified as live and non-ghost. This profile doesn’t exist for every book — but knowing what you’re looking for helps you identify the best available option rather than defaulting to the first plausible category you encounter.
When to Redo Your Category Research
Category research isn’t a one-time activity. Amazon’s category taxonomy changes periodically — new categories are added, existing ones are restructured, ghost categories occasionally get populated or removed. The competitive landscape also shifts as new books enter categories and sales patterns evolve. Reviewing your category placements every three to four months is a reasonable cadence for most authors, with a more thorough audit any time your book’s BSR changes significantly or you notice your organic discovery has dropped.
If your book’s sales plateau after a strong launch, category reassignment is one of the first things worth investigating. Authors sometimes find that switching one category from a high-competition broad placement to a lower-competition specific niche reactivates organic discovery at their current sales velocity — the same number of daily sales that was invisible in a competitive category might rank them in the top 20 of a better-matched niche category. Before investing in additional advertising to rescue a plateauing title, audit the categories first. It’s the free fix that’s often overlooked.
Before any category or metadata changes, make sure your book description is as clear and genre-accurate as possible — Amazon’s algorithm reads your description as a category signal. A professionally proofread description sends cleaner signals and converts better from every category browse placement you earn.
