The fifth Author Earnings Report was released this week, and it tells a starkly different tale about the state of the ebook market.
As an independent survey of the ebook market, the Author Earnings Report is often a useful tool for cross-checking the industry surveys. It has its issues (I don't trust the revenue figures) but each report has proven useful at telling us about the relative shares of the ebook market; what's more, this time around the report delves into the prevalence of ISBNs.
To begin with the report showed that indie titles made up about 26% of the Kindle Store's best seller-list on 21 January:
From that base, the report estimates that around half of the copies sold in the Kindle Store were published by indies. Given that it is difficult to estimate the impact of KU, feebie offers, and the multitude of other details that influence the best-seller list, I have less faith in this chart, but I also have no other data to contradict it:
That's a lot ebooks sold by a segment of the industry which didn't exist 10 years ago, but that's not the best part.
No, my favorite part of this report is the section on ISBNs.
A lot of industry reports are based on the assumption of ISBNs being used throughout publishing as a standard identifier for books. A book without an ISBN is difficult for Bowker and other companies to track, and now we have an idea about just how much is slipping by without being counted.
The numbers folks behind the Author Earnings Report checked all 120 thousand titles which made up this survey group, and they found that 30% of the ebooks sold in the Kindle Store lacked an ISBN.
That means that any market estimate dependent on ISBNs could be off by a minimum of (3/7) 42%, and it could worse than that.
There's no way to know for sure, but at least now we have a better understanding of what we don't know.