How Apple May Inadvertently Boost eBook Linking

"The net interprets censorship as damage and routes around it." John Gilmore, 1993

The official word from Apple finally came out today, in their press release announcing in-app subscriptions.

In addition, publishers may no longer provide links in their apps (to a web site, for example) which allow the customer to purchase content or subscriptions outside of the app.

Assuming that this limitation will be applied to the Kindle App, it means that the "Shop in Kindle Store" button will disappear, and similar features in other ebook reader software, such as Nook, Sony, and Kobo will disappear as well.

You can go elsewhere if you want to read apocalyptic whining about Apple's imperious ways. What I want to focus on is how the net will route around this damage. The net will route around this damage by making more links.

At O'Reilly's Tools of Change for Publishing Conference, I was able to spend some time with Keith Fahlgren, a partner at ThreePress Consulting. He's part of a group that has worked on the improvement of linking capability in EPUB 3. A Public Draft of the specification was released today by IDPF.

Since EPUB3 is based on HTML5, all the outbound linking that you would expect from a web page is already built into EPUB3 (as well as earlier versions of EPUB). Ebook reader apps available on iOS and Android use the "Webkit" webpage renderer for ebooks in EPUB. (Kindle devices use Webkit to render web pages and WebKit is used by Amazon to render Kindle ebooks (in mobi format) on  hardware other than their own.) So it's clear to me, at least, that even if ebook reader apps can't have "Kindle Store" buttons, the apps will be able to present "Kindle Store" links inside the ebook content. I'll bet you anything that Amazon is loading up ebook content with Kindle Store links: "If you like this book, perhaps you'd like this one". They'll even have specialized shop-books containing Kindle store links available for free. Ditto the others.

Publishers aren't going to like Apple's power-play. But neither will they like having their content getting hijacked to promote individual ebook stores. There will therefore be a great deal of pressure for the creation of vendor-neutral, customer friendly ways to link to ebooks from within ebooks, one that Apple can't ban because doing so would break Safari.

Here's where it gets tricky. If a customer has already purchased the linked-to book, it's pointless to send them out to a ebook store, they should connect their copy of the ebook. But figuring out whether a consumer already has the book is messy, given the state of ebook identification. There are many other use cases for linking to a specific chapter or paragraph inside an ebook.

Unfortunately, doing this sort of linking is not a solved problem. EPUB3 adds one tool that will help. A new required metadata property, dcterms:modified,  will help identify the epub in the case where it has been modified- in the past it was poorly specified what should happen to the epub identifier if the file was modified. With EPUB3, it's now clear that EPUB documents are identified internally at a level above the ISBN (different DRM wrappings of the same EPUB file often require different ISBNs) but below the "work".

There's still a lot of apparatus that will need to be built, both inside and outside of EPUB, for linking to work the way it should. Being able to decide which ebook to target will require external mechanisms. Perhaps some linking organization along the lines of Crossref be formed; perhaps a more wikipedia-ish database collaboration will suffice. In any case something like xISBN supercharged for ebooks will be needed. Fahlgren told me that without a strong use case to drive the solution, the EPUB group has had a hard time going very far in their linking development.

A true ebook linking solution would need to include Amazon, of course, and since they've not been using EPUB, it seems to me that ebook linking won't get done by the EPUB group itself. Amazon hasn't had much use for EPUB in the past, but now Apple may have handed the ebook technology community a giant use case for interoperable ebook linking.

Happy Day-After-Valentines-Day, EPUB!