Disclosure: this post is written by the team behind KDP Quick Scout. Neither choice below requires our tool, we mention it once at the end where it’s relevant.
Every KU-vs-wide argument in an author forum turns into the same two comments: someone posts their wide revenue percentage, someone else posts their KU page-read total, and both walk away convinced they’re right. Neither number means anything without the other, and neither means anything without the genre, book length, and launch timing that explain it. That’s the argument nobody’s having.
How Kindle Unlimited works
Enrolling in KDP Select puts your ebook into Kindle Unlimited and makes it exclusive to Amazon, no other ebook retailer, for a rolling 90-day period. You don’t sell the book to KU subscribers, you get paid per page they read, through something Amazon calls KENP (Kindle Edition Normalized Pages).
The payout rate isn’t fixed. Amazon puts KU subscription revenue into a monthly fund, then divides that fund by the total pages read across every enrolled book that month. The result has hovered in the $0.004 to $0.005 per page range recently, roughly $4 to $5 for every 1,000 pages read. There’s a cap of 3,000 KENPC pages per reader per book, so a reader who fully finishes even a very long novel still only counts up to that ceiling.
In exchange for exclusivity, KU enrollment gives new releases a visibility boost during the first 90 days: better algorithmic placement, access to Kindle Countdown Deals, and inclusion in KU’s own browse and recommendation surfaces.
How going wide works
Wide means distributing your ebook to Kobo, Apple Books, Google Play, Barnes & Noble, and dozens of smaller stores, either directly or through an aggregator like Draft2Digital or PublishDrive. You earn a standard royalty per sale, typically 60-70%, at each store. No exclusivity requirement, and no per-page math, you get paid the same whether someone reads one page or the whole book.
Wide’s upside isn’t usually “more revenue on day one.” It’s diversification: your income isn’t tied to one platform’s algorithm or fund size, and some markets (Kobo in Canada, for instance) have real readerships you can’t reach through Amazon at all.
The real trade-off
Strip away the ideology and the decision usually comes down to a handful of concrete factors. Take a 400-page cozy mystery as a running example, a genre where a large share of readers already carry a KU subscription and browse almost exclusively through it.
Genre and reader habits. If most cozy mystery readers in your target audience already have KU, going wide doesn’t reach a new audience, it just removes your book from the app they’re already browsing. A thriller or romance aimed at a more purchase-driven audience is a different calculation entirely.
Series length and reading speed. Page-read payouts reward long books that get finished. That 400-page cozy mystery, if most KU readers finish it, earns differently than a 150-page novella would under the same per-page rate, because there’s simply more page count to be paid for. Short, standalone books usually do better under a per-sale wide royalty.
Launch timing. The 90-day visibility boost is real and mostly wasted if you enroll a book that’s been out for a year with no marketing push behind it. It’s most valuable in the first enrollment window right after a new release.
How much you already know about your numbers. This is the one most people skip. Enrollment is a rolling 90-day commitment, not a permanent one, you can run a cycle in KU, then opt out and go wide, or the reverse. The mistake isn’t picking KU or wide, it’s picking one and never checking whether it worked for that specific book.
A common myth worth retiring
“Wide always earns more per copy, so it’s always the better deal.” This treats a per-sale royalty and a per-page royalty as if they’re directly comparable, they’re not. Do the math on that same 400-page cozy mystery: two full KU reads at roughly $0.0045/page work out to about $3.60 (400 pages x $0.0045 x 2). One wide sale at a $4.99 price and a 70% royalty pays $3.49. The KU math pulls ahead once total reads cross about one and a half books’ worth of pages, and cozy mystery readers who are already subscribers tend to finish books in a series they like. A rule of thumb that ignores book length, genre, and completion rate isn’t telling you anything your specific book needs to know.
How to check what’s working
Whichever you choose, the useful move is treating the 90-day window as a test instead of a permanent decision. Note your BSR and Kindle price at the start of an enrollment period, and check again at the end. If you switch from KU to wide (or the reverse), that same before-and-after comparison tells you whether the switch moved anything, or whether nothing changed and the debate you had with yourself didn’t matter as much as you thought.
That’s the specific thing BSR and price history tracking is useful for, not picking KU or wide for you, just giving you a real before-and-after instead of a guess. KDP Quick Scout keeps that history automatically if you’re tracking a book already; a spreadsheet with two dates and two numbers works just as well if you’re not.
Neither KU nor wide is the correct answer in the abstract. The correct answer is whichever one your specific book’s genre, length, and launch timing point to, and the only way to know for sure is to check.