It seems AI-generated slop is everywhere these days, from YouTube videos to Instagram reels. Even so, one would not ordinarily expect such low-effort content to start topping bestseller lists.

And yet, this is exactly what is fast becoming a norm, with AI-generated fiction books now commanding a whopping 20% share of total sales in 2026, with a third of new entrants in bestseller lists containing AI content.

An interesting new paper has profound implications for the growing menace of AI-generated slop. The study authors randomly sampled a collection of 14,419 self-published fiction ebooks, running an AI-detection tool from Pangram on the entire text for each of the books in the sample.

The sample was then divided into 3 categories: where the AI-generated text constituted at least 25 percent of a given book's total text, it was classified as "substantial AI," with the "light AI" ranking reserved for books where the AI content was less than 25 percent.

Concurrently, the study authors "matched each book to a proprietary daily sales feed from a BigFive publisher," to glean its daily sales figure over a three-year period.

Armed with this data, the study authors found the following interesting insights:

1. Around 20 percent of the books in the sample across every fiction genre - romance, sci-fi, thriller, etc. - were classified as "substantial AI."
2. Around 33 percent of new entrants in the bestseller lists now contain AI-generated content.
3. Over three years, the volume of books in the fiction genre grew by a whopping 38x cumulatively, while revenue only increased by 9x on a quarter-to-quarter basis.
4. "The more AI books enter a genre, the more ground non-AI books lose."
5. "One author earned $1.7M across 8 titles in 12-months post-release, and the single best-selling AI-heavy book made $643K on 80,000+ copies."
6. Interestingly, the AI books that do succeed contain more rare phrases - albeit ones that already appear in published works - than their successful non-AI counterparts.
7. AI books also seem to be copying from each other a lot more, replete with verbatim overlap.

The essence of the study is that AI-generated books appear to have cheapened the efforts of genuine authors, cutting "what the average human-written book earns in most genres and pushed human titles down the bestseller ranks."

What makes this paradigm truly deplorable is the fact that AI labs, in their quest to feed their data-hungry models, have reportedly bought rare books in bulk, scanned them by ripping off their spines, and then shredded the original manuscripts. This is an irreplaceable loss, all to feed models with data they've never seen.

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