This question has caused more arguments in indie author circles than whether a full stop goes inside or outside the closing quotation mark. It's also one of the first decisions you'll face as a self-published author, and there's no universally right answer. But there is a right answer for your specific situation, and it depends on a few things most people don't consider.
What the Terms Mean
Kindle Unlimited (KU) means enrolling your ebook in Amazon's KDP Select programme. Your book is available to KU subscribers — who pay a monthly fee to read as many books as they like — and in return, Amazon pays you per page read. The catch: your ebook must be exclusive to Amazon. You can't sell it on Kobo, Apple Books, Google Play, or anywhere else.
Wide distribution means selling your ebook on multiple platforms. Amazon, Kobo, Apple Books, Google Play, Barnes & Noble — the lot. No exclusivity. You keep your options open.
The Case for KU
If you write genre fiction — romance, thriller, science fiction, fantasy — KU is where a significant chunk of your readers live. These are voracious readers who devour books by the dozen. They'll take a chance on an unknown author because it costs them nothing beyond their monthly subscription.
For a debut author in a popular genre, KU can generate far more income from page reads than you'd earn from sales alone. I've had months where page-read income outstripped sales income by three to one.
KU also gives you access to promotional tools like Kindle Countdown Deals and Free Book Promotions, both of which can spike your visibility if used at the right time.
The Case for Going Wide
If you write literary fiction, non-fiction, or anything outside the main genre categories, wide distribution often makes more sense. KU readers tend to favour genre fiction, and the per-page-read rate can fluctuate month to month — Amazon sets it, and you have no say in the matter.
Going wide also reduces your dependence on a single platform. If Amazon changes its algorithm, its terms, or its royalty structure — and it has done all three without much warning — wide authors feel the impact less than those who've put every egg in Amazon's basket.
There's also the long game. Building a readership across multiple platforms takes time, but once established, it provides a more stable and diversified income.
The Honest Truth
For most indie authors starting out in genre fiction, KU is the faster path to income and visibility. The subscribers are there, they're hungry for new books, and they'll read yours if you present it properly. You can always pull out of KU after a 90-day enrolment period and go wide later.
For authors in non-genre categories, or those with an established readership spread across platforms, wide makes more sense from the start.
What I Did
I started in KU. It gave my early books the visibility they needed to build an audience. Once I had a back catalogue and a mailing list, I moved some titles wide while keeping my newest releases in KU for the initial launch period. That hybrid approach works well for me, though I know plenty of successful authors who are all-in on one side or the other.
The point is to make the decision consciously, based on your genre, your goals, and your current situation — not based on what someone in a Facebook group told you worked for them.