Who needs an ISBN? Survey shines a light on massive ‘shadow’ self-publishing market

Almost a third of ebooks bought in the US do not use ISBN numbers and comprise a massive ‘shadow market’ which is being ignored in the publishing industry’s reports.

The latest survey from best-selling author Hugh Howey’s Authorearnings.com is a monster-sized analysis of the ‘invisible’ sector brought about by self-publishing.

It reveals that 33% of all paid ebook unit sales on Amazon.com are self-published. The figures also show that in the middle of last year, self-publishers as a whole took over the leading share (40%) of all ebook earnings generated on Amazon.com while Big Five Authors fell back to second place with 35%.

The latest Author Earnings’ report is based on a data snapshot of 120,000 of the best-selling ebooks on Amazon, giving a data sample of around half of Amazon’s daily ebook sales.

For daily unit sales, the survey shows that at least a third of all paid ebook unit sales on Amazon.com are indie self-published ebooks but the real number is almost certainly several percent higher. This is because the survey does not include Uncategorized Single-Author Publisher ebooks as indie self-published titles, although they are self-published, as it would be too time-consuming to check all 10,000 of them.

When it comes to consumer spending, at least a fifth of all consumer dollars spent on ebooks on Amazon.com are being spent on indie self-published ebooks.

Indie authors take top spot for ebook earnings

The survey’s focus is on author earnings through royalties rather than publisher earnings and it finds 40% of all dollars earned by authors from ebooks on Amazon.com are earned by indie self-published ebooks.

The indie share of author earnings includes 8% from Kindle Unlimited borrows of indie books. The survey crowdsourced borrow-buy ratios from hundreds of indie authors in KU and found they averaged 1:1, which is backed up by analysis of KU payouts.

Trend shows continued growth of indie market and flaws in trad industry surveys

Over five consecutive Author Earnings’ data snapshots over a period of 12 months, a clear trend has shown the continued growth of indie market share compared with traditionally published ebooks.

Hugh Howey takes issue with traditional publishing industry surveys which have failed to take into account the massive non-ISBN sector of the market which now amounts to at least one-third of the ebook business.

Traditional surveys collect self-reported data from a small subset of publishers and use average per-title sales numbers to project the size of the entire ebook market by multiplying average per-title sales numbers by the number of active ebook ISBNs.

Author Earnings found that:

  • 20% of Amazon’s overall Top 10 selling ebooks did not have ISBNs

  • 16% of Amazon’s overall Top 100 selling ebooks did not have ISBNs

  • 34% of Amazon’s overall Top 1,000 selling ebooks did not have ISBNs

  • 37% of Amazon’s overall Top 10,000 selling ebooks did not have ISBNs

None of the major ebook retailers requires an ISBN to publish an ebook.

Top non-ISBN titles outsell ISBN competition

The figures also show the top several-thousand indie titles without ISBNs outsold and outearned the top several-thousand indie titles with ISBNs.

  • The top 3,830 indie titles without ISBNs sold an average of 42 copies a day and earned their authors an average of $70 a day.

  • The top 3,830 indie titles with ISBNs sold an average of 24 copies a day and earned their authors an average of $52 a day.

A growing number of traditional publishers outisde the Big Five are also opting not to use ebook ISBNs. Nearly 25% of indie ebooks published in 2011 used ISBNs, but only 13% of indie ebooks published in 2014 use ISBNs.

87% of ebooks bought that were published in 2014 by indie author-publishers did not have ISBNs.

In 2011, 92% of the best-selling ebooks published by non-Big-Five trad publishers used ISBNs, but in 2014, only 70% of the best-selling ebooks by non-Big-Five traditional publishers used ISBNs.

Relying on ISBNs to estimate the ebook market means only 10% of unit sales and 7% of gross consumer ebook dollars appear to be going to self-published books.

Ebook market share is being underestimated

Author Earnings points out that the huge ‘invisible’ sector makes several recent industry survey claims dubious, including the ‘finding’ that ebook sales are ‘plateauing’ or ‘declining’.

It says we could be seeing a progressive shift of ebook market share away from the traditionally published ‘visible’ portion of the industry that uses ISBNs toward the ‘shadow industry’ of self-published ebooks with no ISBNs.

Author Earnings says the real ebook market share is far higher than industry reports of 30% and print books make up a far smaller portion than the claimed 70%.

There’s an even bigger than usual amount of fascinating and very useful information together with an array of charts in the full survey which you can see at Author Earnings. All figures and charts in this article courtesy of Author Earnings.

Self-publishers break out of genre

Indie writers earning more than trad authors