When an author first sells their books, one of the things outlined in their contract is format rights as well as the royalties that they'll make on said formats. Now, we talked about those different royalties in a previous essay, discussing how much money an author can expect to make off of each individual book they sell depending on if it's a physical copy, audiobook, or ebook. What we did not talk about is how many of each of those formats you can expect to sell.

I'm not talking about the number of books sold, obviously, because no one has any idea how many will sell; not you, your agent, the bookstores, or even your publisher. What I'm talking about is the percentage of overall sales that will wind up coming from each of the formats published. This may seem like a trivial topic, but as we outlined in that previous essay authors make vastly different amounts of money off the sale of a mass market versus, say, an audiobook or hardcover.

To keep things simple, I'm going to ignore stuff like C-format, foreign copies, or library copies and focus on the big ones: hardcover, ebook, audiobook, mass market, and trade paperback. This is where it starts to get complicated so pay attention, because all of this is going to make your head hurt a little bit.

As I alluded before, different contracts may include different rights being sold at different times, perhaps even to different companies. This is mostly divided between physical books and ebooks being sold together, with audiobooks maybe or maybe not getting picked up at the same time (it used to be divided even further, because ebooks used to not be a thing and when they first were, some publishers didn't bother with them, but I don't think that happens much any more). In addition, publishers don't put out every book in all three physical formats. My books, for instance, came out in hardcover and trade paperback in the US and hardcover and mass market in the UK. Many of my author friends are out in trade paperback and mass market without hardcover, or mass market alone.

This means that getting any real solid data on this kind of thing when you don't have access to the databases of a publisher is really difficult. When I decided to do this essay I sent emails off to a handful of my author friends asking if they'd be willing to share their format percentages. The first thing I learned is that most authors don't keep track of these numbers with the same obsessive zeal that I do. For some, looking at number sales causes anxiety, for others, they're just not interested.

The second thing I learned was, as mentioned above, I'm not going to be able to give you a solid spread of consistent formats. Let's get into the numbers so I can show you what I mean. First we'll look at some of my friends who were able to give me sales percentage data:

Wesley Chu's Lives of Tao sold 40% ebook, 60% mass market. No info on audio.

Myke Cole's Control Point sold 49% ebook, 51% mass market. No info on audio.

Stephen Blackmoore's Dead Things sold 53% ebook, 47% mass market. Audio sold separately and will be out later this year.

Jason Hough's Darwin Elevator sold 70% ebook, 20% mass market, and 10% audio.

I like this data because it's all from book one in a new series with different audiences that may overlap a bit, and all concerning the same formats. Just from these four, you can see a 30% spread on format sales—wowza. However, this data also makes it look like it'll be simple to analyze this kind of stuff over multiple authors. To disabuse you of this notion, let's take a look at a few more:

Django Wexler's Thousand Names sold 62% ebooks, 38% hardcover/mass market, and no data on audio.

Django's middle grade (8-12 years) Forbidden Library sold 93% hardcover and 7% ebook in the UK.

Michael Sullivan's Theft of Swords sold 45% ebooks, 26% trade paperback, and 29% audiobooks.

Mark Lawrence's Prince of Thorns sold 55% ebooks, 45% everything else.

Missing data! Different formats! Murky reports! Various audiences! This way surely lies madness. Mark commented that his ebook percentage has climbed across all five of his books ending with 78% of sales for his latest, while Myke said his was steady across the three books and then the mass market leapt up for the fourth. Even trying to figure out how sales will go within a single series seems anyone's guess.

Okay, so I've offered up a bunch of other people's numbers. To further illustrate that point about a series, here are some of my own:

Promise of Blood

US hardcovers: 10.31%

US ebooks: 63.21%

US audio: 13.31%

US trade paperback 13.17%

Crimson Campaign

US hardcovers: 20.59%

US ebooks: 55.92%

US audio: 15.15%

US trade paperback 8.33%

Autumn Republic

US hardcovers: 18.53%

US ebooks: 62.76%

US audio: 18.71%

You can easily see the first problem with looking at this data even across my own series: the trade paperback of each book came out eight months or so after the other formats, so the data is skewed against that format and in the case of Autumn Republic, it isn't even out yet. It would be far more accurate to look back at this in, say, five years.

(One interesting thing to note is that the system is built that way so that people who buy the trade of an earlier book will hopefully buy hardcover of the newest release. The big jump in hardback percentage from books one to two reflect this. I only have about half the sales data for hardcovers of Autumn Republic, so I suspect you'll see another large jump there once I do get that data.)

If you compare my data with the data from my author friends above, you can see the problem. The differing formats means that we're comparing apples to something vaguely but not entirely apple-like. If you decide to get fancy and throw in other rights, even just the World English ones, things get even more crazy.

Let's toss another set of numbers in there for fun: John Scalzi publicly posted the numbers for his book Redshirts about seven months after it came out. They were 45% ebook, 34% hardcover, and 21% audio.

Because I keep obsessive spreadsheets on these things I was able to go back and check and see what the US numbers for Promise of Blood were after seven months. They were 68% ebook, 24% hardcover, and 8% audio. You can see the significant difference between Scalzi's numbers and my own. The problem with trying to interpret the reason for those differences is it's all conjecture: it was not his first book, so he had more people buying hardcover; for part of that time my ebook was on sale for $1.99; his audiobook had been pushed hard by Audible; etc. It's going to be a combination of all of the above, of course, but how much of each.

The conclusion I come to, presented with all this data, is that there's no "rule of thumb" that can cover all of publishing. Keep in mind, most of the numbers I gave you above are from genre authors writing to an adult crowd. Numbers change dramatically across YA, middle grade, romance, westerns, etc. I'm not saying it's hopeless. If a new author were to ask me what they can expect, I'd probably tell them they'd sell around 50% in ebooks—and I might be close. But some authors gather giant followings among audiobook listeners or hardback collectors that skew the numbers.

I don't really envy the people who have to sort through this mess for a living, even if I do find it fascinating.