Generative AI floods and dilutes the market for books
A study of 14,419 self-published genre-fiction books on Amazon from 2023 to 2026 found that books with substantial AI-generated text (>25%) make up a large share of the catalog but a smaller share of sales. However, they are gaining sales share over time and capturing top-rank positions. The number of books with observed sales grew 19.2-fold, while quarterly revenue grew only 8.9-fold, causing revenue per selling book to fall. Books with no AI text lost the most ground in genres with high AI diffusion, especially where Kindle Unlimited availability is high.
Generative AI is increasingly used to produce book-length fiction at near-zero cost, leading to a surge in self-published titles on Amazon. An analysis of 14,419 books from 2023 to 2026 reveals that AI-generated content is prevalent, with books containing over 25% AI text comprising a significant portion of the catalog. Although these books initially account for a smaller share of sales, their market share is growing, and they are displacing human-authored books from top sales ranks. The market expanded rapidly in terms of titles (19.2-fold increase in books with sales) but revenue grew more slowly (8.9-fold), resulting in declining revenue per book across most genres. The impact is most pronounced in genres with high AI adoption and high Kindle Unlimited availability, where non-AI books suffer the greatest losses.
The study employed full-text AI detection on a large corpus of self-published books, using a threshold of >25% AI-generated text to classify books as substantially AI-produced. This detection method allowed for a quantitative assessment of AI's penetration into the commercial book market, revealing a clear trend of increasing AI content over time and its correlation with sales dynamics.
The findings indicate that generative AI is disrupting the self-publishing industry by enabling mass production of low-cost content, which pressures revenue per title and challenges traditional authors. The growing acceptance or inability to distinguish AI-generated books suggests a potential long-term shift in consumer behavior and market structure, particularly in genre fiction and subscription-based platforms like Kindle Unlimited.
For publishers and platforms, the rise of AI-generated content presents both opportunities and risks: lower content acquisition costs but potential brand dilution and legal challenges. Authors may need to adapt by leveraging AI tools or focusing on niches less susceptible to automation. The study highlights the need for transparency and possibly new business models to sustain quality and diversity in the book market.
If current trends continue, AI-generated books may dominate certain genres, further eroding earnings for human authors and potentially leading to market saturation. Future signals to watch include changes in Amazon's content policies, the development of more sophisticated AI detection tools, and consumer backlash or acceptance. The economic viability of human-authored genre fiction may increasingly depend on differentiation and platform interventions.