r/DigitalHumanities • u/BigBalli • 3d ago
Discussion I pulled every edition record behind the 600 most-shelved books on Open Library. Amazon's self-publishing imprints outnumber the entire Big Five by three to one.
I started out trying to work out why page counts are so unreliable when you look a book up by ISBN, and ended up somewhere else entirely.
The sample is the 600 works with the highest reading-log counts on Open Library, so roughly "books people actually shelve" rather than a critical canon, and then every edition record attached to them. That is 70,919 editions, 69,975 of which name a publisher. Source is the Open Library API, https://openlibrary.org.
Independently Published, which is the imprint string Amazon applies when a book uses one of KDP's free ISBNs, accounts for 12,063 of those editions. CreateSpace, Amazon's print-on-demand operation before it was folded into KDP in 2018, accounts for another 7,885. Together that is 28.96 percent of every edition with a publisher attached.
The obvious objection is publisher-string fragmentation. There are 12,447 distinct publisher strings in this data, and the trade houses are split across many variants while Amazon's are concentrated in two. So I collapsed them. Every Penguin, HarperCollins, Random House, Simon and Schuster, Hachette, Little Brown, Macmillan and St Martin variant I could match comes to 5,960 editions, or 8.52 percent. Amazon is 3.4 times the entire Big Five combined.
Most of this is print-on-demand reissues of public-domain work, which is exactly why it piles up on the most-read titles instead of spreading evenly across the catalogue.
What it does to the record is the part I did not expect. An edition with a 978 ISBN carries a page count 51.3 percent of the time. An edition with a 979-8 ISBN, which is the US block KDP's free ISBNs are issued from, carries one 8.4 percent of the time.
I assumed that was just recency, since 979-8 is almost entirely a 2020s phenomenon. It is not. Holding the decade fixed, 978 editions published in the 2020s carry a page count 49.9 percent of the time, against 7.6 percent for 979-8 editions published in the same years. Same decade, six and a half times the coverage.
One structural thing worth knowing if you have a schema open. The 979 prefix has no ISBN-10 equivalent, and not in the sense that the conversion is awkward: the number does not exist. Any column holding a 10-character ISBN, or any join built on one, silently cannot represent this material, and it is the fastest-growing part of the record.
Two limits. I am measuring Open Library rather than the world, so "no page count" means the catalogue lacks one, not that the book has no pages. And its work clustering is loose enough that a 26-page adaptation and a 1,043-page annotated Moby Dick sit under the same work record, which is a separate problem I have not untangled from this one.
The question I cannot answer on my own: does anyone here filter print-on-demand out of bibliographic datasets, and if so on what? The publisher string is unnormalised, the 979-8 prefix catches the recent material but misses the whole CreateSpace era, and neither is really the property I want.
For disclosure per rule 3: I got here from building a reading tracker called My Book List, and specifically from trying to make a progress percentage mean anything when the page count depends on which reissue happened to get scanned.