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Three Possible Problems With Bowker’s Self-Pub Stats

D7855497040_b3a0c9be7c[1]id you catch the hot self-pub story today?

Bowker released the stub of a new report which analyzes the ISBNs registered to self-published titles in the US in 2012. They found a marked increase in the number of ISBN’s registered – 59%, in fact.

I don’t have the report, but I do have the press release and I thought it would be a useful exercise this morning to show how it’s not that easy to separate out self-pub US titles from the rest of the global market.

BTW, if someone could get me a copy of the report I will be very grateful.

Here’s the relevant part of the press release:

A new analysis of U.S. ISBN data by ProQuest affiliate Bowker reveals that the number of self-published titles in 2012 jumped to more than 391,000, up 59 percent over 2011 and 422 percent over 2007. Ebooks continue to gain on print, comprising 40 percent of the ISBNs that were self-published in 2012, up from just 11 percent in 2007.

Now, I could point out that Bowker’s statistics miss the majority of the self-published titles because it only tracks ISBNs (most self-pub titles lack ISBNs), But I wrote that last year so rather than repeat myself I think it would be more constructive to point out new problems in the report.

Bowker’s press release is framed with the assumption that all of these ISBNs went to titles published in the US. It also assumes that all of the ISBNs went to self-published titles. Neither assumption is completely true, and I can prove it with one word:


This distributor buys ISBNs in bulk from Bowker and then provides them to its customers. It is well-known as the biggest self-pub ebook distributor in the world, but that title glosses over the real situation. Smashwords will work with everyone – including publishers. That means that you cannot automatically assume that all of the titles distributed by Smashwords are self-published.

I bet you could make a similar argument about ISBNs registered to self-published titles (perhaps the author started their own imprint) via POD services like CreateSpace and Lightening Source, but I am less familiar with those services so I will let the point lie.

Getting back to Smashwords, I will also point out that this is actually an international service, not one focused sole on the US market. They distribute to ebookstores all over the world, so the ebooks they handle don’t exactly meet a strict definition of being based in the US market (one detail which Bowker assumes in the press release).

Smashwords will also accept ebooks from anyone with an internet connection almost anywhere in the world, and that makes it a little hard to come up with a US-only figure without first culling through their files.

Did Bowker take these issues into account before issuing this report? I don’t know, and I would love to find out. If anyone has a copy of the report, please check and then leave a comment.

Or better yet, slip me a copy of the report and I will read it myself.

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Peter Turner October 10, 2013 um 11:18 am

It’s also important to keep in mind when considering ISBN counts (which is all Bowker is really reporting) is that some unique identifier is needed to sell a book whether it’s print, eBook, self-pub’s or traditionally pub’d. Kindle doesn’t requie ISBNs (which you have to purchase) and instead uses their own ASIN ("Amazon Standard Idenification Number"). Traditional pubs assign a unique ISBN for each format. Self-pub authors tend to skip this as it’s an unnecessary expense at Kindle and some other eBook retailers. So, in esssense, ISBNs are a pretty meaningless way of considering the volume of books being published or even a trend line.

SteveH October 10, 2013 um 3:48 pm

Yeah Nate, the devil is in the exact details they are reporting. As a Bowker customer myself, I know you can buy ISBN blocks that can be assigned to any format later. The second step of the process is to register the number 'owned' to a product via their database which does require tons of specifics including format (print vs. ebook) and country released to, etc.
So if in fact they are stating numbers attributed to ebook format registered ISBNs then they are only a sub-set percentage of all U.S. ebook releases. (Apple doesn’t even require them anymore to self-pub).

Nate Hoffelder October 10, 2013 um 4:32 pm


Tell me, do you think they do any data validation? If an author made up a publishing imprint would Bowker notice?

BTW, I know digital publishers that don’t get ISBNs for their ebooks, so it’s not just authors who are bypassing the system. Any guesses how many do the same?

Rob Siders October 10, 2013 um 8:54 pm

Authors make up publishing imprints all the time, as a goodly number of my clients go whole hog and start legal business entities to serve as their publishing houses. I’m sure that Bowker notices, but whether they assign that any weight or even care is a mystery to me. Más datos sobre el auge de la autopublicación – June 2, 2015 um 11:21 am

[…] Igualmente, la internacionalización de algunas de estas plataformas como la propia Smashwords hace que la medición sólo a través de los datos del ISBN no pueda ser exacta a la hora de querer cifrar sólo en Estados Unidos, como muy bien señalan en The Digital Reader. […]

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