A new study analyzing 14,419 self-published e-books shows AI-generated books are rapidly increasing on Amazon, displacing human authors despite lower revenue per title. The research, conducted by the researchers, found that books with substantial AI content make up 20% of the catalog but account for only 12.1% of sales and 11.3% of revenue. This trend is reshaping the market, with AI-generated titles now making up 31% of new Top 25 entries on the platform. The study highlights how AI content is diluting the market, with revenue per book falling for titles with no detected AI text in seven of eight genres. The researchers used the Pangram v3.3 detector to classify books based on their full text, identifying AI-generated content with a false-positive rate of 0.04 percent.
The findings suggest that AI-generated books are not only flooding the catalog but also altering consumer behavior. Between Q1 2023 and Q1 2026, the cumulative catalog grew 38.3x, while the number of titles selling per quarter grew 19.2x. Quarterly revenue only grew 8.9x, indicating a significant drop in revenue per book. This decline is most pronounced in genres with high Kindle Unlimited availability, where the revenue-share lead of books with no detected AI text is 8.4 percentage points smaller than in genres with low Kindle Unlimited availability. The researchers attribute this gap to genre-specific traits rather than directly to Kindle Unlimited itself.
The study also reveals how AI-generated content is outperforming human authors in terms of visibility and sales. The share of new Top 25 entries with substantial AI content rose from near zero to 31% over the study period, while the share of books with no detected AI text that stayed in the Top 25 dropped to about 28% before settling around 62% by the end of the study. The sales share of books with no AI text fell from nearly 100% in early 2023 to about 60% in Q2 2026. Output is concentrated among a handful of prolific producers, with 287 of 385 author identities increasing their monthly output after their first AI book. The highest-grossing pseudonym earned $1.7 million in gross revenue across eight titles.
Source: thedecoder
