Kindle Unlimited for Indie Authors: What You Need to Know Before You Enroll
Have you ever wondered why some authors choose to publish only on Amazon? If you've been poking around in the self-publishing world, you've probably come across Kindle Unlimited (KU)—a subscription service that sounds like a dream for readers and a golden ticket for authors.
But what is Kindle Unlimited really? And more importantly, is it right for you?
To make an informed decision it’s important to first take a good hard look at how KU works, why Amazon calls the shots, and what it means for your career as an author. Whether you're dreaming of bestseller status or just trying to earn your first royalty check, understanding KU is critical before you click “Enroll.”
By the end of this article, you’ll be able to make an informed, confident decision about whether KU fits into your publishing plan.
What is Kindle Unlimited (KU) and KDP Select?
Let’s start with the basics, because KU can be a bit slippery if you’re new to the game.
Kindle Unlimited is a subscription service for readers. For $11.99 a month (as of this writing), subscribers can download and read as many KU books as they want—just like Netflix, but for books.
On the flip side, KDP Select is the program for authors. When you enroll your book in KDP Select, Amazon adds it to the KU catalog—and in return, you agree to distribute your ebook exclusively through Amazon for a 90-day period (renewable).
That means no Apple Books, no Kobo, no Barnes & Noble, no sales from your own website. Nada.
So, Kindle Unlimited is the reader-facing benefit, while KDP Select is the author-facing contract.
There are three major things to know about Kindle Select.
Now here’s where it gets interesting—and complicated.
When readers download your book through KU, you don’t get paid per download. Instead, you get paid per page read.(!?)
The Page-Read Formula
Amazon uses something called KENP (Kindle Edition Normalized Page) to standardize page counts. It doesn’t matter if your book is formatted with big fonts or tiny margins—Amazon calculates a normalized page count using its own secret sauce. This is not your printed page count or Word document count.
When a reader flips through pages in your KU-enrolled ebook, each page they read earns you a fraction of a cent. This is known as the KENP rate, and it fluctuates monthly. The average over time hovers around $0.0045 per page.
Let’s do the math. If your book is 300 KENP pages, and a reader finishes the whole thing, you’ll earn around $1.35 from that read.
Now here’s the twist: Amazon doesn’t publicly disclose how KENP is calculated or verified. There is no third-party oversight or transparency. It’s a black box.
The Global Fund
The payout rate comes from what’s called the KU Global Fund, a giant pot of money Amazon sets aside every month—again, without explaining how the amount is determined. In recent years, this fund has surpassed $50 million monthly, but that total gets divided among all enrolled authors worldwide based on pages read.
So, according to Amazon, you’re not just getting paid by the reader—you’re sharing a communal pie with thousands of other authors, and Amazon is the only one baking it. Keep that in mind as we move on.
The Exclusivity Clause: A Double-Edged Sword
Here’s the big catch. When you enroll your book in KDP Select, you must promise not to sell or distribute your ebook anywhere else—not even on your own website.
You can still sell paperbacks and audiobooks wide. But the ebook must remain exclusive to Amazon during the 90-day term.
From a strictly business perspective, this is a horribly bad deal.
If you were selling anything else, widgets, let’s say, and you approached a store about carrying your widgets on their shelves, and the store owner were to reply:
“Sure, but I
control the price, the margin you get, the way that’s calculated, the product placement,
the payment arrear, and the length of the contract. Oh, and you have no way of
auditing any of it, I can change the terms whenever I want, and you can’t sell
it anywhere else. Have we got a deal?”
If you knew anything about business you’d laugh your way out the door. A savvy business doesn’t just hand over complete control of their product to a single distributor, especially one that controls the pricing, royalties, and payout methods. Its just not a good deal, and outside of KU I doubt you would be able to find a similar one anywhere else.
On top of this you have no legal recourse if Amazon changes the terms, withholds royalties, or suspends your account. The Terms and Conditions are vague, written in Amazon’s favor, and subject to change at any time.
That’s why many seasoned authors say enrolling in KU is like "renting shelf space from Amazon in exchange for your independence."
Let’s break this down further.
A little history lesson.
Amazon launched Kindle Unlimited (KU) on July 18, 2014. At that time it offered over 600,000 titles, including many self-published works through Amazon's Kindle Direct Publishing (KDP) platform. The major traditional publishers declined to participate, so KU relied heavily on indie authors.
Initially, authors were paid per borrow, meaning if a KU user read at least 10% of the book, the author received a flat rate. Devious indie authors immediately invented ways to game the system by breaking up large books into smaller ones, publishing short stories in high volume, and employing click farms to download and “read” their books en mass. In response Amazon changed KU in July 2015, when they introduced a per-page-read payment system, known as KENP (Kindle Edition Normalized Pages). This shift aimed to better align author compensation with reader engagement and curtail abuses such as short books padded with filler content.
Over the years, Kindle Unlimited expanded its catalog to over 4 million titles, including audiobooks through Whispersync and Audible narration. The service also rolled out in multiple countries beyond the U.S., including the UK, Germany, India, Canada, and more. Although KU still lacks many Big Five publisher titles, Amazon has continued to court independent authors and small presses with promotional tools, bonuses, and visibility benefits tied to KU exclusivity.
Today, Kindle Unlimited remains a cornerstone of Amazon’s self-publishing ecosystem. It offers a lucrative platform for some indie authors who can rank highly and earn significant revenue from page reads and All-Star bonuses. At the same time, KU continues to evolve amid ongoing debates about exclusivity, fair compensation, and its impact on the broader digital publishing landscape.
It’s led to a lot of unanswered questions. Let’s explore some of them.
What’s a page-read and why is the payout .0045?
When KU switched to its current iteration in 2015 there was a massive amount of speculation, almost all of it online in public forums, as to what the payout would and should be. Authors on such chatrooms as KBoards bickered back and forth for months about what would be fair and what they would accept before enrolling their books.
Amazon, of course, was listening.
As a result, the KENP rate fluctuated back and forth for some time before finally settling down at .0045 per page. Yes, it supposedly changes monthly, but if one were to measure the average year-by-year over the last decade one might be surprised to find that the yearly rate and overall rate are very much the same. The average KENP rate is .0045. It was ten years ago, and it still is today.
Amazon, with a little help from the authors themselves, quickly figured out the sweet spot when it came to the KENP rate. They know exactly where it needs to be to both attract authors to the system while keeping the authors they currently have re-enrolling.
This leads to the next question.
The Global Fund.
According to Amazon they “set aside” over 50 million dollars every month in a fund and then divide that fund among the authors who have enrolled their books in Kindle Select.
There’s few problems with this.
As deep as Amazon’s pockets are, “setting aside” 50 million dollars is not something company’s do. That kind of money is put to work. Even if it were simply invested in the S&P 500 and making around 8% that amounts to around $330,000 every thirty days. Small by comparison, but still a substantial amount of money, especially when you take into account other factors, which we’ll get into later.
Most businessmen/authors realized long ago that the Global Fund is likely nothing more than a marketing gimmick. There is no Global fund, there is simply what Amazon is willing to pay, which is .0045 per page-read.
Payment arrears.
Since we’re on the subject of large amounts of money laying around let’s consider Amazon’s payment arrear of 60 days post. Other sales platforms pay out 30 days post or even 15 days, so why does Amazon need so much time?
To answer that we can look to the insurance industry. Anyone who has ever filed a claim or maybe even sued an insurance company is immediately met with a stalling technique. Insurance companies don’t make money from their agents, they make money from their lawyers and actuaries whose job is to make sure the company pays out no more than it has to and to construct its policies for maximum profit. There’s a lot of math involved.
Let’s say your house is destroyed due to faulty roofing materials. The case is open and shut. The company who made the materials know it. The lawyers on both sides know it. The bank knows it. What does the insurance company do?
Math.
They first figure out what the probable out-of-court settlement will be. They then pull that money from the general fund and park it in a six-month investment. Then they stall. No matter how aggressive your lawyers might get, nothing is going to happen until that six-month investment has run out. Once it has, the lawyers come to the table, work out a deal, and inform their boss of the number. The last thing they do is inform the recipient that the check will arrive in 30 days.
30 days? Why?
So they can park that six-month investment into a 30-day investment and make even more money, thus lowering the end amount they were forced to pay. In short: Time=Money, and its all in their favor.
By waiting sixty days to pay authors Amazon has sixty days
to invest those authors profits. Every sale you make amounts to a sixty-day loan
to Amazon.
So why do it?
Because its Amazon.
Like it or not, Amazon is king. They hold approximately 50% of all new print book sales in the US. They also have an estimated 80% share of the e-book market. In the overall book distribution market, including self-published titles and Kindle Unlimited, Amazon's share can reach up to 85%. Kindle Unlimited is estimated to have 4 million subscribers alone.
On top of that, it’s hard to find a better bookstore. Where else can you find one with almost every book ever written on the shelf, each of them available for purchase with a single click, and open 24 hours a day seven days a week? Amazon’s user interface is so good that even readers who buy on other sales platforms use Amazon to find their next book. It’s without a doubt the world’s biggest bookstore.
For some authors, that alone is worth the price. What the KU deal lacks in transparency it makes up for in sheer volume. For many authors that’s enough to sway them.
The Benefits of KU for Authors
Despite the downsides, many indie authors find success in KU. Let’s break down why.
1. Visibility: KU titles often get preference in Amazon’s algorithm. They’re easier to rank, more likely to be featured, and may qualify for additional promo tools.
2. High-Volume Reads: In binge-heavy genres like romance, sci-fi, fantasy, and thrillers, readers devour books rapidly. That means more page reads, more royalties.
3. Simplified Marketing: Instead of marketing across multiple platforms, you can focus all your efforts—and ad dollars—on one place: Amazon.
4. Amazon Ads Synergy: While controversial, Amazon ads are often necessary to thrive in KU. Some authors describe it as pay-to-play, meaning you have to spend on ads to gain visibility, then hope KU royalties balance it out.
The Downsides of KU for Authors
Let’s not sugarcoat it. KU isn’t a perfect model. Here’s what you’re giving up:
1. Your Rights (Temporarily): KU restricts where you can sell your ebook, and this limits your global reach. You’re cutting off entire markets and potential income streams.
2. Unpredictable Income: The KENP rate changes monthly, and you can’t control how much you earn per page. That makes financial forecasting a headache.
3. No Transparency: You’ll never know how your KENP total is calculated or how Amazon determines the size of the KU pot.
4. Market Dependency: You’re tying your success to a platform you don’t control. If Amazon changes the rules, you’re stuck playing catch-up.
KU vs. Book Sales: The Full-Sale to Page-Read Ratio
Here’s a question every author should ask: Would I earn more from a full-priced ebook sale than from a KU read?
Often, yes. A typical $4.99 ebook sale nets you about $3.49 in royalties. A full KU read of that same book might earn just $1.20 to $1.50, depending on length.
That means KU books need to be read more often to break even. If you’re not in a genre with high-volume readership, this math may not work in your favor.
Shorter books suffer the most, especially novellas and quick reads.
Tracking KU Performance with ScribeCount
Now for the good news: ScribeCount makes it easy to monitor KU metrics, so you’re not guessing your way through enrollment.
With ScribeCount, you can:
Track page reads by book across date ranges
View your KENP royalties alongside ebook and paperback sales
See trends across multiple Amazon marketplaces
Compare KU performance to wide sales (if you switch later)
Determine the Full Read to Full Sale Ratio for each book in KU
This kind of clarity helps you make data-driven decisions instead of relying on gut instinct—or Amazon’s vague dashboard.
ScribeCount also includes a Full Read to Full Sale Ratio Calculator built into the bookshelf telling you how many page-reads it takes to equal one sale of your book. There’s also a calculator in the Tools section that allows you to plug in KU rates and page counts to see what the projected payout would be. These tools and features are there to help you both track your books profits and project what future books may earn in KU.
Common Misconceptions About KU
One myth we hear often:
“If my book’s in KU, it must be doing well—it’s getting tons of downloads!”
Not quite.
Downloads don’t equal page reads. And partial reads don’t always generate meaningful royalties. That’s why it’s vital to use tools like ScribeCount to monitor actual engagement, not just surface-level activity.
Another myth: “Exclusivity guarantees success.”
Again, not true. KU gives you access to a big pool of readers, but you still have to market your book—and competition is fierce.
KU by Genre: Where It Works and Where It Doesn’t
Some genres thrive in KU:
Romance
Erotica
Urban fantasy
LitRPG
Cozy mystery
Thriller
These genres attract binge readers—KU’s sweet spot.
Remember, Amazon was the first company to target the voracious reader, and they still do so today with KU. (To better understand this read (or re-read) the Article “Knowing the Industry” in the “Basics” section of Author Resources)
Other genres—like literary fiction, memoir, nonfiction, and poetry—often perform better when sold wide, to readers who prefer to buy rather than borrow.
Amazon Ads and KU. Pay to Play?
The growing consensus among indie authors is that books enrolled in KU have a ceiling when it comes to sales, page-reads, and general exposure without an accompanying Amazon Ads campaign. Surveys and the available data have shown that the top sellers in KU all have ad budgets that number in the thousands per month.
This amounts to a pay-to-play system where simply listing a book on Amazon is no longer enough. Authors must now engage with Amazon Ads to gain visibility, especially if they want to benefit from KU's page-read payouts.
For a detailed breakdown of Amazon Ads see our article on that subject.
Conclusion: Is KU Right for You?
Kindle Unlimited is a one-sided deal, no question. Amazon holds the power, the data, and the money. The exclusivity clause limits your freedom. The payout system lacks transparency. Ads are necessary for discoverability. And yet, for some authors, it works.
If you’re just starting out and want to build a quick audience in a popular genre, KU can be a great stepping stone. If you’re writing slow-burn fiction or nonfiction with niche appeal, wide distribution might serve you better.
Ultimately, your publishing goals—and your willingness to trade control for convenience—will guide your decision. Your tolerance for risk is also a factor.
Many authors split the difference and do both, enrolling one series in KU and publishing others wide. This is probably the best way to determine which option is best for you and your books. This results in additional time and effort devoted to tracking ads and making adjustments to your marketing, but the time spent will likely make future decisions much easier.
So approach KU with caution and some knowledge. Enroll with intention. Have a plan. Use tools like ScribeCount to track your progress. The thing to remember about KU is it has to be renewed every 90 days. That’s enough time to test the program, make some adjustments, and track your progress. If that data tells you that KU is not for you don’t be afraid to pivot and opt out. If it works look into scaling it up.
It’s your business, you have to do what’s right for it and you.
