Kasspian’s honest read
Amazon KDP is genuinely free to start, but it's a saturated market now flooded with low-effort and AI-generated books where the vast majority earn next to nothing, so it's tough to win without an existing audience, a defensible niche, or writing good enough to earn reviews and rank.
Who actually pays
Amazon readers browsing or searching for a book: a huge audience, but one with near-infinite cheap alternatives.
Riskiest assumption
That your book gets discovered and bought in a market where millions of titles compete and quality is hard to signal cold.
Fastest test first
Publish one genuinely good book in a niche you understand and see if it earns reviews and organic sales before scaling a catalogue.
The pitch is seductive (no printing cost, global distribution, passive royalties) and a small number of authors do build real income, especially in niche non-fiction or with a series and an audience. But the median outcome is bleak: most self-published books sell a handful of copies to friends and then vanish, because discovery is everything and the shelf is effectively infinite.
It's gotten harder, not easier. The market is saturated, low-content and AI-generated books have flooded categories, and Amazon's discovery rewards reviews and sales velocity you don't have on day one. The people who win treat it as a real product business: a sharp niche, genuine quality, and usually an audience or email list to drive the first wave of sales and reviews. As a get-rich-passive scheme it almost never works; as a slow build on top of a real niche or following, it can. Quality and distribution decide it, not the number of titles you upload.
This is the read on the category. Your version isn’t the average. Get the honest call on your exact idea, with live market data, in about 90 seconds.