The 2019 sales report released in February by the Swedish Publishers Association and the Swedish Booksellers Association offered some good news for publishers. Overall, revenue for the Swedish trade book market rose a modest 1.1% last year over 2018. Normally, a small increase in annual sales would suggest a stable market. But not in this case.

The report also showed that sales at Sweden’s bricks-and-mortar bookstores declined 4.4% in 2019. Online and book club sales decreased 5.2%. And the supermarket channel plummeted 9.9%. Countering those declines, publisher revenue from digital subscription services—a fast-growing sector in which Swedish companies are taking the lead globally—surged 36.2%.

The jump in publishers’ digital subscription revenue in Sweden is largely being driven by digital audio, which is by far the hottest sector in the trade book business worldwide. But e-books are also in the mix, making up about 8% of sales in the channel. And the 2019 report underscores just how important digital subscription has become for Swedish publishers.

In 2019, four Swedish subscription platforms—Bokus Play, Bookbeat, Nextory, and Storytel—were responsible for nearly 21% of trade publisher revenue in Sweden. Without subscription services, trade revenue in 2019 would have declined 5.3%. With subscription services, not only was revenue up slightly but unit sales also rose 4.9% over the previous year.

The question, of course, is whether the current model of all-you-can-eat digital subscription access is sustainable. And on that score, the Swedish market is serving as a lab for the wider publishing world. On one side of the debate, some publishers are concerned that digital subscriptions will cannibalize traditional book sales, hurting publishers by offering lower compensation for each unit sold and enabling heavy readers to spend less on books without bringing in enough new consumers to make up the difference. Penguin Random House took this view earlier this year when it pulled its titles out of these all-you-can-eat subscription platforms.

On the other side of the debate are companies like Storytel, the leading Swedish subscription platform that is now present in 20 countries and counts more than 1.1 million customers. Storytel executives insist their subscription service is attracting consumers who would otherwise never be reached by the traditional publishing industry.

The Swedish market is serving as a lab for the wider publishing world.

In the 2019 annual report, Maria Hamrefors, chairwoman of the Swedish Booksellers Association, expressed concern about the rapid shift to subscription services. “The statistical research shows that nearly half of all books are now sold via digital subscription services, and that sales of physical books are sinking,” she wrote. “The digital development has also resulted in a powerful devaluation of the book, and I believe this is really worrying. The average income per book read in these digital subscription services is about a quarter of the average price of a hardcover.”

The math gets even more complicated for publishers, considering that subscription platforms pay based on books “consumed” rather than books sold. Storytel, for example, divides its audiobooks into units of time, and a title is considered to be consumed (and thus paid for) when subscribers have listened to the total number of units an audiobook has—no matter which units, or which subscribers. In other words, if 10 separate readers each listen to one of the 10 units of the same audiobook, that accounts for one copy sold, just as it would if one listener had listened to all 10 units. That’s a potentially serious adjustment for the industry to navigate, as those with shelves of unread books know.

Still, some observers contend there was no real cannibalization in the Swedish market in 2019—only changes in the market share of the various channels. After all, publisher sales were up slightly for the year, suggesting that the growth in digital subscriptions is offsetting declines in the industry’s traditional channels, at least for now, while also growing the consumer base for book content.

There’s a case to be made on both sides. “It’s not unreasonable to believe that increased digital sales could have a negative impact on the sales of printed books,” observed Isa Widerståhl, publisher at Albert Bonniers, in the 2019 Swedish annual report. At the same time, she noted, digital subscription makes more titles available to more consumers than traditional retailers ever could. “One of the many nice things with digital audiobooks is that you can reach consumers at times when you would not otherwise reach them.”

Carlo Carrenho is the founder of PublishNews in Spain and oversees international projects for Word Audio in Sweden.