Summary of “Amazon’s control over ebook sales data should upset everyone in publishing”

Many of their authors are writing and publishing books, and finding massive audiences, without being actively tracked by the publishing industry.
According to one estimate, last year 2,500 self-published authors made at least $50,000 in book sales across self-publishing platforms, before the platforms’ cuts.
The information asymmetry between Amazon and the rest of the book industry-publishers, brick-and-mortar stores, industry analysts, aspiring writers-means that only the Seattle company has deeply detailed information, down to the page, on what people want to read. So an industry that’s never been particularly data-savvy increasingly works in the dark: Authors lose negotiating power, and publishers lose the ability to compete on pricing or even, on a basic level, to understand what’s selling.
Amazon doesn’t report its ebook sales to any of the major industry data sources, and it doesn’t give authors more than their own personal slice of data.
A spokesperson from Amazon writes by email that “Hundreds of thousands of authors self-publish their books today with Kindle Direct Publishing,” but declined to provide a number, or any sales data.
“NPD PubTrack Digital tracks ebook sales but because it is a publisher data-share model, the data does not include self-published ebooks,” writes NPD’s Allison Risbridger by email.
Bookstat extrapolates sales data from book rankings and sales history, provided by authors, and estimates sales per author and book throughout the day, with a self-reported margin of error of 5%. Bookstat estimates that in 2017, there were half a million self-published authors who sold at least one book, and a total of 240 million self-published ebook units sold.
As the founder, who still asks to remain anonymous, notes, “There’s really no way to wrap your arms around how many authors there are, including the ones who are not selling, including the ones who are out of print on the traditional publishing side.” By his estimate, self-published books in the US were worth $875 million last year, about $700 million of which was ebooks.

The orginal article.