This article was first published in the Autumn 2021 issue of The Author, the journal of the Society of Authors. I would like to express my appreciation to James McConnachie for commissioning the piece, and to him and his colleague Carlotta Eden for their graceful editing.

At the start of June, a world first was announced in the UK. Authors would be compensated for sales of secondhand copies of their books, as part of the AuthorShare scheme developed by the Authors Licensing and Collecting Society (ALCS), the Society of Authors (SoA), World of Books and Bookbarn International.

Unsurprisingly, the scheme was welcomed by authors. Hannah Berry, from the AuthorShare steering committee, described it as 'really heartening to see that there is a will to support creators beyond the initial publication.' AuthorShare is a wholly positive development, but is a starting point, not an end. Copyright is exhausted on the first sale of a book and there is no legal basis for creators to be paid for subsequent sales—AuthorShare’s payments come from a £200,000 fund established voluntarily by the retailers involved.

More retailers could yet join the scheme, however. And, arguably, should, as the trade in secondhand books is booming. The market is growing at a rate of between 12–15% per annum, much faster than the market for new books. Companies like World of Books and MusicMagpie are leading the development of a ‘circular economy’, making it easier for individual consumers to sell unwanted books and increasing the pool of secondhand volumes in circulation. The strategy is paying off: World of Books turns over £45 million and MusicMagpie more than £150 million, though a spokesperson approached for this article was unable to confirm what proportion of that comes from books, as opposed to old mobile phones, game consoles and other items.

All of this makes the size of the secondhand market a question of acute interest to authors. Others outside the sector are interested too. After nearly 25 years in bookselling and publishing, I now work as an independent consultant, and a client recently asked, 'how big is the secondhand book market in the UK?' It became clear that simple questions do not always have simple answers.

Nielsen BookScan records nine in ten new book sales but does not currently track the secondhand market. Small wonder: to do so for new books requires integrating point-of-sale data from nearly 50 major sources, plus a far larger number of independent retailers. Achieving even a lower level of coverage for secondhand books would likely be an order of magnitude more complex. There are more than 11,000 charity shops in the UK, for which books are an important revenue stream, and countless individuals selling their old books online.

What links all of these vendors, from large platforms such as World of Books or Bookbarn International to individuals, is the importance of Amazon as a sales platform. We know that in the first quarter of 2021, 55% of Amazon’s total unit sales were from third-party sellers using Marketplace, rather than Amazon itself. Amazon does release statistical tidbits of this sort, serving its purpose in attracting vendors to its platform, but it does not release meaningful data on secondhand book sales. Such data would invite scrutiny of Amazon’s market share, which includes not only Marketplace sales but also (the Amazon-owned) specialist secondhand books and art site AbeBooks, at the higher end.

Building a Market Estimate

Robust industry reporting may be absent, then, but it is still possible to build a picture of the market. When private equity house Bridges Fund Management acquired a majority stake in World of Books in 2016, it valued the online secondhand book market at around £200 million, growing at around 15% per annum. More recent annual growth has been closer to 12%, but growth even at that lower level implies an online market of more than £350 million.

Offline sales would have to be added on top. Given the range and number of outlets, this is the hardest segment to estimate. There are a few data points, however, which really underline the importance of the charity sector for secondhand sales. Oxfam, which describes itself as the largest chain of secondhand booksellers in Europe, saw book sales of £19 million last year through 750 stores. The British Heart Foundation (BHF), which has a similar number of shops, was unable to disclose turnover but confirmed that it sells around 4.5 million books per annum. If you apply those figures to research from the Charities Retail Association, which found a median price of £2.53 for secondhand books, it would imply the BHF earned revenue of around £11.4 million from secondhand book sales. With these figures in mind, an estimate of £100-150 million in UK offline sales seems plausible.

More recently, research carried out by market intelligence specialists M-Brain on behalf of World of Books gave an estimated total market value of at least £563 million in 2025. Using the same annual growth rate of approximately 12%, that would correspond to nearly £360 million today. This was the low end of a range of estimated figures: applying the same process to the high-end estimate would suggest a market of nearly £450 million today.

In terms of top-down estimates, there is an extraordinary lack of public data on the UK market. There is some much older data for the US market, published by the Book Industry Study Group, which suggested that secondhand sales represented around 8% of new sales. This was undertaken in the early years of Amazon Marketplace and is undoubtedly too low today. More recent data from sources including Statista and private conversations with an investor and several American publishers suggest that 16–18% is a more plausible proportion. If that proportion held true for the UK market also—where new book sales were around £2.5 billion last year, according to the Publishers Association—it would correspond to a secondhand books market worth £400–450 million.

All this is an estimate based on nominal figures. In the absence of a more comprehensive survey, it is reasonable to suggest the UK secondhand book market is worth between £360-500 million, which amounts to somewhere between 14 and 20% of the market for new books. This raises two important questions for authors and publishers.

The fundamental question for authors is what they get paid. It is to be hoped that a better understanding of the size of the market will help to make the case for other retailers to join AuthorShare.

There are of course other benefits to the secondhand trade. Ultimately, reading as a habit, regardless of format, should be encouraged. Charity retailers in particular highlight the sustainability benefits of their business model—and who among us would not prefer a book to find a reader rather than a place in landfill or a recycling plant?

But in a context where the secondhand market for print books is growing at 12–15% and the market for new books is growing at around 1%, where secondhand inventory is sold online alongside the new, and where charity shops enjoy a structural advantage over the independent bookseller next door in being exempt from business rates, the balance between those segments is clearly of great concern to those who earn their living from their words.

Dark Matter

Kobo CEO Michael Tamblyn memorably described self-published ebooks as the ‘dark matter of the publishing world’ on the basis that they were an important force but not visible through traditional industry measures. If the description holds true for that digital format, it certainly applies to secondhand sales as well. Researching this piece, I was struck by how little publishers know about the secondhand trade. Nick Bates at Bookbarn International, like me a former publisher, told me what a gap in knowledge he thinks it is for our former colleagues. Similarly, SoA Chief Executive Nicola Solomon remarked that it is ‘fascinating how little the publishing world engages with it.’

That we should understand and be engaged with readers has been part of publishing orthodoxy for years. In that context, that a fast-growing segment of the market, worth perhaps half a billion pounds, is less well understood is genuinely surprising.

Meanwhile, the fundamental questions over author earnings will not go away. The AuthorShare initiative does at least demonstrate that there are ways for secondhand booksellers and authors to work together.