From About Ebooks:
In January 2022 the American Association of Publishers, which represents mostly mainstream consumer book publishers, reported that among their members ebook sales accounted for 11.3% of sales revenue. Bear in mind that this figure relates to revenue from the sale of popular, consumer ebooks released by established trade publishers. It largely excludes sales of educational and technical titles, and sales through self-publishing platforms such as Kindle Unlimited. And those categories typically comprise a much higher percentage of digital sales. But if you’re curious about the books you see in your local bookstore, then 11.3% is a useful data point. In October 2021, research outfit NPD Group reported that, “e-books account for 18% of sales, or more than one in six books sold.”
Consider Mark Williams’ argument in a December 2021 where he says, “AAP reports October ’21 ebook REVENUE was worth $84 million. For the same month Kindle Unlimited paid out $39.8 million in ROYALTIES. Just how big is the real ebook market no-one wants to talk about?” This simple comparison suggests that overall (at least US) ebook market share by revenue might be as much as double the AAP’s reported stats — something like 28%.
. . . .
In January 2020 the UK’s Bookseller estimated global ebook sales to be 19% of total book sales by revenue, and a whopping 36% by unit sales (number of books sold). This massive figure is somewhat driven by the number of back-list ebooks offered by publishers for free or under $1.00.
Link to the rest at About Ebooks