Secondhand Book Sales Are Surging, and AI Training May Be Why

Independent booksellers across the UK and Ireland say they are seeing a sudden surge in unusually large bulk orders, and many suspect the buyers are not readers at all. According to Gizmodo and AOL, booksellers are shipping crates of secondhand books to distant warehouses in quantities that do not match ordinary retail demand, and the likely explanation is AI companies buying up print books to feed their training pipelines.

What booksellers are seeing

Stuart Manley, who runs Barter Books in Northumberland, said a single recent bulk order from a Canadian company matched what he would normally sell in an entire week, telling reporters he has "never seen the like of this after 30 years in the second-hand book trade." Other sellers, including David Tobin of Walden Books, have reported similar unexplained mega-orders, ranging from obscure academic texts to old paperback novels, with buyers who show little interest in condition or edition, the details that usually matter most to a collector or reader.

The AI training connection

The suspicion traces back to a 2025 US court ruling in the case brought against Anthropic by a group of authors. Judge William Alsup found that using purchased books to train the Claude AI model was "exceedingly transformative" and therefore protected as fair use under US copyright law, even though the authors had never agreed to have their books used that way. When related court documents were unsealed last month, they revealed that some of the books bought for training were destroyed after being digitized, once their content had been extracted.

No company has confirmed being behind the current wave of bulk orders, and booksellers themselves are largely guessing based on order patterns rather than direct confirmation. But the timing, the odd mix of titles, and the sheer volume all point in the same direction: books published before generative AI reshaped the internet are now treated as premium, verifiably human-written training material.

Why this matters for you as an author

If you have a backlist title sitting out of print, or a self-published book that only sells a handful of secondhand copies a year, this is worth knowing. A secondhand sale pays you nothing no matter who buys it, that is how the used book market has always worked, but it is a different thing to learn that your book may be quietly feeding a language model's training data without your knowledge or consent. With a US court having already ruled that kind of use falls under fair use, there is little an individual author can do to stop a specific purchase from happening.

What you can control is how transparent you are about your own use of AI going forward. As AI training and AI detection questions keep colliding with the publishing world, from surprise court rulings to canceled book deals over AI suspicion, being able to explain clearly how you write, and what role AI played in it, is becoming part of an author's job. Our guide on AI writing ethics for authors walks through the questions worth having answers to before a publisher, platform or reader asks them.

PageWriter Studio keeps that kind of record for you automatically: a style profile trained on your own voice, and a clear trail of what you drafted versus what you revised, so you always know exactly how your book came together. If you want to try it on your next project, you can start a free trial.