Which book formats sell best?
The answer might surprise you (but probably not)
Welcome to the free newsletter of David (D. V.) Bishop, author of the Cesare Aldo historical thrillers set in Renaissance Italy. This time: which book formats sell best?
Return of the (book) stats
A few newsletters back I dissected my income as a self-employed writer, looking at different revenue streams over the past six tax years. Being quite a nerd, this got me thinking about the various ways in which my Cesare Aldo historical thrillers are being published. In what format do the novels sell best, and why might that be?
Pictured: the frequently problematic Josh Lyman. Doesn’t The West Wing seem quaint now?
Each Aldo appears in five different formats. In the UK they are initially published in hardback, as an audiobook and an ebook. Elsewhere, the initial print format in places like Ireland, Australia and Aotearoa New Zealand is a trade paperback. It’s the same size as a hardback, but doesn’t have the bulky hard cover or a dust jacket.
[When books are sold in UK airports there is often a section called Airport Exclusives. Those oversized books are a trade paperback, priced halfway between a hardback and a standard paperback. They are lighter than a hardback so easier to take on holiday, and very tempting if you can’t wait for the paperback edition to come out.]
Up to a year after a novel’s initial publication the paperback will finally appear. Many paperbacks come out within six or seven months of hardback, but sometimes readers have their patience tested further. The Darkest Sin paperback is the most extreme example for my historical thrillers, appearing 364 days after the hardback! And some books are published as paperback originals, without ever having a hardback edition.
An aside: I deliberately end my Aldo novels on a cliffhanger or twist to make readers eager to get hold of the next book in the series. Quite a few people have told me they enjoyed an Aldo paperback so much they couldn’t wait for its successor to appear in the same format and jumped straight to hardback. I am #sorrynotsorry about that.
Enough talk, give me numbers
I’m using the numbers for City of Vengeance because it’s been on sale the longest and offers the best sense of how sales shift over time. It was published in hardback, trade paperback, audiobook and ebook in February 2021, with the paperback following in January 2022 (although many paperback sales got counted as Jul-Dec 2021 royalties).
The pie chart above clearly shows which two formats are leading the way in volume of sales. Paperbacks have been 41% of all copies sold, with ebooks a strong second as a third of sales measured by volume. One in ten copies sold has been an audiobook, with the rest split between hardback and the trade paperback. So far, so expected.
But if you compare sales volume with sales royalties, I’ve made more from ebooks than paperbacks despite selling fewer of them. Why? Because the ebook royalty rate is higher. Similarly, my total royalties from hardbacks is higher than from audiobooks despite smaller sales. [Audiobook royalties are divided between author and narrator.]
The vast majority of hardback and trade paperbacks sell during the initial months of a book’s lifespan. Once a paperback comes out, few shops keep stocking older formats for obvious reasons: the paperback is cheaper and more portable. Bookshops send back unsold hardbacks and trade paperback, a dreaded process known as ‘returns’.
Those returned books are set against an author’s cumulative sales, meaning it will take longer to earn out their advance (read more about earning out here). As you can see in the bar chart above, the trade paperback lost sales due to returns while City’s hardback continued selling a little, even after its paperback edition came out.
Compare that with ebook and audiobook sales (below) and you’ll notice a significant difference. While hardback and trade paperback drop off dramatically, other formats released in February 2021 have continued to sell steadily. These are evergreen, boosted by occasional promos such as 99p Kindle offers. Indeed, lifetime audiobook sales of City have now overtaken the individual totals for both hardback and trade paperbacks.
Paperback is the other evergreen format, one with the potential to keep selling for years, so long as there is demand and a publisher keeps it in print. Before City of Vengeance came out, my editor told me the aim was for paperback sales to eventually be ten times the number of hardbacks it was expected to shift. In fact, the hardback sold nearly double its estimate, while the paperback is close to its original target.
The line graph below shows most paperback sales were in the first six months, but they keep ticking over and get a boost each time another Aldo novel is published. That prompts new readers to discover the series, and quite a few go back to the start so they can read from the beginning. This nicely sustain sales for City of Vengeance.
City of Vengeance will always be the bestselling Aldo, barring outside intervention. If a later book won a big prize, that would increase sales a bit. But should a new Aldo book be chosen for a high-profile book club like Richard & Judy, or BBC2’s Between the Covers TV show, that could well see it overtake City (a boy can dream, can’t he?).
The City of Vengeance paperback does face a limitation audiobook and ebook formats do not: shops have only a limited amount of shelf space. They will stock the newest title in a series (called frontlist in the trade), and keep a selection of perennial sellers on the shelves, known as backlist. In publishing terms, City is now strictly backlist.
While the paperback of City keeps selling, bookshops will keep stocking it. As noted above, a new Aldo novel each year helps boost interest in my backlist. But any long series soon hits a tipping point where few shops stock the complete backlist. That’s not a problem digital formats like audio and ebooks face, they don’t need shelf space.
Many bookshops are happy to have all four Aldo paperbacks published to date on their shelves, but by 2027 there will be six titles in the series. That becomes a problem, and another reason why authors of series fiction ofte turn to writing standalones. Right, that’s enough numbers for now. I have a new Aldo novel to be writing!
If you’ve been forwarded this newsletter by a friend, feel free to subscribe. But if you no longer wish to receive it, click unsubscribe at the bottom of the page.







Thank you, that explains so much! Even if I get the audio book or an eBook I still must have a hard copy of the book to add to my collection.
I have a frustration when they change the cover format for series partway through. Suddenly my collections don't match.
Excellent analysis - very useful!