Tech media outlet Wccftech published a blog post yesterday (July 30), reporting that a recent paper found that about 33% of new books on the bestseller lists contain artificial intelligence-generated content.
Researcher Tuhin Chakrabarty posted on X on July 28 that his team randomly selected 14,419 bestselling self-published genre novels sold on Amazon from 2023 through March 2026, then used Pangram's artificial intelligence detection tool to examine the full text of each book.
The study divided the samples into three categories: works in which artificial intelligence-generated text accounted for at least 25% of the entire book were classified as having “substantial AI content”; works with less than 25% were classified as having “light AI content”; and works in which no AI content was detected were classified as having “no AI content.”
The study found that about 20% of the samples across genres including romance, science fiction, and thrillers contained “substantial AI content.” The article also cited that AI-generated novels accounted for about 20% of total novel sales in 2026, while about 33% of new entries on the bestseller lists contained AI content.
In terms of market size, the number of novels increased 38-fold cumulatively within 3 years, while quarterly revenue grew only 9-fold. The study said that the more AI-generated novels there are, the more likely non-AI novels are to lose market share.
The paper concluded that AI-generated content has lowered the average income of works by ordinary human authors across most novel genres and has also caused works by human authors to fall in the bestseller rankings.
Reference source above
Generative AI floods and dilutes the market for books