What’s a book? It’s whatever you want it to be

As we’ve mentioned a number of times, the evolution of the book-publishing business has been accelerating recently, with more authors doing an end run around the traditional industry by self-publishing — or even setting up their own e-book stores, as Harry Potter creator J.K. Rowling has done with her new Pottermore site. Now media companies seem to be showing an increasing interest in publishing their own e-books using content that they have already created, moves that are taking them into the growing market in between full-length books and magazine-style pieces.

The latest move in that direction comes from Ars Technica, which is part of the Conde Nast magazine empire that includes Wired magazine and The New Yorker. The technology blog, which has become well known for its exhaustive reviews of new Apple (s aapl) hardware and software by author and programmer John Siracusa, is offering its latest review — an in-depth look at Apple’s new operating system, code-named OS X “Lion” — as an e-book using the Kindle Single program. The book (which is really just a long magazine article) costs $5, and is more or less identical to the version that is on the Ars website.

Paying for convenience?

So why would someone want to pay $5 to read something that they could read for free on a website, or download via their browser and read offline via Read It Later or some other service? That’s a good question (Fortune tried something similar with a recent feature on Apple, but it wasn’t available online at all). Whatever the answer might be, Ars Technica editor Ken Fisher told the Nieman Journalism Lab on Friday that more than 3,000 people had decided to do just that within 24 hours of the review being available online. Said Fisher:

I was surprised by how many people told us they read the review online and they just wanted their own copy to go back to. Or they just bought it as a tip-jar kind of thing.

It may have helped that Siracusa’s review is a lot closer to being a book than it is just a regular review in an online magazine — it is more than 27,000 words in length, which is split up over 19 pages. That’s a lot of text to read on a website, and some readers said that they downloaded the Kindle (s amzn) single just to save themselves from having to read all those pages on a computer. Fisher said the magazine also saw some new users sign up for its $5-a-month premium subscription plan, which disables advertising and lets users download any of the magazine’s articles as PDFs.

Ars Technica isn’t the only one to see the value of real-time (or close to real-time) publishing of e-books based on its content: as Jeff Sonderman of the Poynter Institute noted recently, some traditional media organizations have also been going this route with quick e-book versions of some of their long-form features — in some cases, published to take advantage of the frenzy of interest around a news event. The Washington Post and ABC News, for example, both published e-books based on the killing of Osama bin Laden, and the Boston Globe published a three-book series based on the arrest of notorious gangster James “Whitey” Bulger.

Newspapers and other media companies have been publishing quickie books to take advantage of news stories for some time now — but the ease with which content can be turned into a Kindle single via Amazon’s platform means a book can be produced within hours instead of days or months. Prices for an e-book might be a lot lower, but if more are sold because the news is fresher in people’s minds, then it can still be worthwhile. It may not be a huge source of revenue, but it’s something.

Costs of publishing are far lower

Not only that, but the costs of producing these books are orders of magnitude lower: the Globe executive in charge of the Kindle offering told Poynter that the Whitey Bulger book was produced from stories that had already been written for the newspaper, and all it took was someone to format the content in the right way for Amazon’s system, some light editing, and the creation of a cover image. The newspaper “easily recovered those costs in a few days” of selling the book, the Globe VP said.

This kind of “format shifting,” in which a newspaper or magazine takes content that has already been published and reformats it for the Kindle or some other device, makes a lot of sense. That content can theoretically reach readers who might never have picked up the newspaper or magazine, or who missed it when it was first printed, or who want to read it in book form while sitting on their couch or at the beach rather than on a computer. And if the cost is low enough, they will be willing to pay for that convenience.

The “single”-length e-book is a market that seems to be growing, with new entrants such as the Byliner service and LongReads. In many ways, it’s just a recognition of the different ways people are reading now, with Kindles and iPads and other devices. Instead of being a discrete object, the book is becoming much more of a fluid concept, and there is opportunity in that transformation for those who want to discover it.

Post and thumbnail photos courtesy of Flickr users Mike Licht and Kelly Teague