KDP Free Days: The Complete Strategy for Maximum Downloads and Sales
Five free days per enrollment period sounds simple. But the difference between 50 downloads and 5,000 — and between dead traffic and real book sales — comes down entirely to strategy.
What Are KDP Select Free Days?
KDP Select Free Days are a promotional tool available exclusively to authors enrolled in KDP Select (Amazon's 90-day exclusivity program). Each 90-day enrollment period includes 5 free promotion days that you can use however you choose — all at once for a 5-day run, or split across shorter windows.
During a free promotion, your book appears at $0.00 on Amazon. Readers can download it without paying. You earn no royalties on free downloads — the value comes from rank visibility, download volume, reviews that may follow, and the post-free paid sales bump.
Optimal Timing: When to Run Your Free Days
Timing is the biggest strategic variable in a free promotion. The wrong timing produces thousands of downloads with no lasting effect. The right timing creates a lasting rank boost and review pipeline.
New series — Book 1 launch
Highest ROILet your paid launch run first (2–4 weeks) to build initial reviews and sales rank data. Then use free days to spike downloads and expose the series to thousands of new readers. The series funnel — book 1 free, books 2+ paid — is the most powerful use of free days.
Standalone or backlist title
Good ROITie free days to a larger promotional event — a new book release, an author birthday promotion, or a genre-wide sale. Free days for a standalone need an anchor event to generate post-promo reviews and follow-on engagement.
Series mid-run — book 2+ free
Good ROIMaking an earlier series entry free just before a new installment launches is a strong re-engagement tactic. Readers who missed book 2 download it free and catch up before buying book 4 on launch day.
Debut author — zero reviews
Wait for reviews firstReaders browse Amazon's free list by looking at cover and review count. A free book with 2 reviews still gets ignored. Spend your first enrollment period building reviews with iWrity, THEN run free days when you have social proof to convert downloaders.
Promo Site Stacking: The Complete Directory
The most effective free promotions stack multiple promo sites running simultaneously. Each site reaches a different slice of Amazon's reader base. Submit to as many as your budget allows — 2–4 weeks before your free days begin.
Most sites require a minimum review count (typically 5–10), a minimum rating (3.5–4.0 stars), and 1–2 weeks lead time. Plan submissions before you schedule your free days.
| Site | Cost | Est. Downloads | Lead Time |
|---|---|---|---|
| BookBub Featured Deal | $200–$2,000 | 1,000–50,000+ | 4–6 weeks |
| Freebooksy | $50–$150 | 500–3,000 | 1–2 weeks |
| ManyBooks | $25–$75 | 200–1,500 | 1 week |
| Robin Reads | $30–$80 | 300–2,000 | 1–2 weeks |
| Fussy Librarian | $15–$35 | 100–800 | 1 week |
| eReader News Today (ENE) | $35–$100 | 300–2,000 | 1–2 weeks |
| BookSirens | Free tier available | 50–300 | 1 week |
| Book Cave / FindaWayBooks | $15–$40 | 150–700 | 1 week |
Tracking Downloads and the Post-Free Rank Bump
How to Track Your Free Promotion
Check "Free Units" in your sales report daily. These are your download counts. Update manually — KDP reports aren't real-time.
Monitor your rank on Amazon's free bestseller list. Aim for top 100 overall, and top 10 in your category. Refresh your book page hourly on day 1.
Third-party tools that aggregate your KDP data for cleaner reporting. Useful for comparing promo performance across multiple free runs.
If sites allow custom links, add UTM parameters to track which promo site drove the most clicks. Use Google Analytics on your author website to capture referrals.
Understanding the Post-Free Rank Bump
When your book returns to its paid price after a free promotion, Amazon's algorithm briefly gives it elevated visibility based on the download momentum. This "post-free bump" typically lasts 1–7 days.
The bump is stronger when: (1) you hit the top 100 free overall, (2) you ran a well-promoted campaign with multiple promo sites, and (3) your paid price is competitive for your genre.
The bump does NOT last. After 7 days, your rank returns to wherever your paid sales support it. The lasting value of free days is not the bump itself — it is the reviews and word-of-mouth that accumulate from readers who downloaded during the promotion.
Maximize the bump:
Email your list the moment you go back to paid with a limited-time $0.99 price (if you have KU Countdown Deal credits). Capturing buyers while you are still ranked high from the free run compounds the effect.
Converting Free Readers to Paid Buyers and Reviewers
The organic review rate from free downloads is 0.5–2%. Here is how to systematically increase it — and build a series readthrough machine at the same time.
End-of-book review request
Place a one-page review ask at the very end of your ebook — after the story but before any back matter. Include the direct Amazon review link. Readers who finish your book are your highest-intent reviewers; capture them while the emotion is fresh.
Reader magnet + email capture
Offer a free bonus (prequel short story, character guide, first chapter of book 2) in exchange for an email address. Place this offer prominently at the end of your ebook. Free downloaders who join your email list are far more likely to become reviewers and series buyers than those who remain anonymous.
Series loss-leader: free book 1, paid books 2+
The most reliable strategy for fiction authors. Price book 1 permanently free (permafree) or use free days repeatedly as an ongoing acquisition tool. Amazon series pages display all books together — readers who download free book 1 see book 2 and book 3 immediately. Even a 10% readthrough at $4.99 from 2,000 free downloads equals $998.
iWrity for pre-committed reviewers
Random free downloaders are anonymous with no commitment to review. iWrity matches your book with readers who have explicitly agreed to read and post an honest Amazon review. Using iWrity in parallel with free days gives you a reliable review pipeline — not just a download number.
Frequently Asked Questions
How many KDP free days do I get?+
5 free promotion days per 90-day KDP Select enrollment period. You can use all 5 days at once (a continuous 5-day run) or split them across the period (e.g., 3 days in month 1 and 2 days in month 2). You cannot accumulate unused days across enrollment periods.
Do KDP free days affect my Amazon sales rank?+
Free downloads count toward a separate Amazon free book bestseller ranking — not your paid sales rank. After the promotion ends, the download momentum can temporarily boost your paid sales rank, typically for 1–7 days. This "post-free bump" is stronger when you received a high free-list ranking during the promotion.
How many downloads should I expect from a KDP free promotion?+
Without promotion: 50–200 downloads. With a single mid-tier promo site: 300–1,500. With full promo site stacking (3–5 sites plus email list): 1,000–5,000+. With a BookBub Featured Deal: potentially 5,000–50,000. Most authors without active promotion severely underperform their potential.
Can I run KDP free days every 90 days on the same book?+
Yes. As long as your book remains enrolled in KDP Select, you get 5 new free days with every 90-day renewal. Many series authors run free days on book 1 every 90 days as an ongoing reader acquisition strategy. The returns typically diminish after the first few runs as you exhaust the promo sites' audiences.
Should I use all 5 free days at once or spread them out?+
For maximum download volume and rank impact: run all 5 days consecutively. This keeps your free-list ranking high long enough to be noticed and to climb the charts. Spreading days out dilutes each individual run and makes promo site scheduling harder. The exception: save 1–2 days for a second smaller promotion later in the period.