Today sees the digital launch of Ashley Rawlings and Craig Mod's Art Space Tokyo, a guide to 12 galleries and other cultural spots in and around Japan's capital. The book is great; it's beautifully laid out and features insightful essays by and interviews with people who keep Tokyo's art scene ticking. Almost as absorbing as its contents, though, is the story of how it came to be.

Originally published as a hardcover book, Mod and Rawlings took to Kickstarter in 2010 to fund a reprint and iPad version. The funding was successful, but the eventual iBooks edition never showed up until today — and it's being joined by versions for Kindle and Nook along with a PDF and a free web version. A DRM-free $14.99 bundle of the ePub, mobi, and PDF files is also available.

In an essay entitled Platforming Books, Mod goes into the design process behind each of these versions and outlines how they were tuned to the advantages and limitations of their individual platforms. He also explains the rationale behind offering the book in full for free — the idea is that making such a rich resource of information available online will drive traffic to the point where more people pay for the book than if the content were locked away. It's an unusual business model, but Mod promises to let us know the results at a later date.