From the beginning of Digital Change Thinking Time, which for me goes back to the mid-1990s, “subscription” has been high on the list of future expectations. That’s natural. The subscription model has emerged as the dominant one for cable TV (although there is still some pay-per-use) and Netflix works that way as well. Lots of people subscribe to satellite radio. Rhapsody is a successful subscription service for music. Pandora for music has a free model and a paid model, as does Spotify.

Subscriptions actually have a history in trade publishing too, where they were called “book clubs”. The print book club model, which also depended heavily on the club’s role in curation (or title selection), was doomed by the arrival of online bookselling. But O’Reilly has demonstrated the common sense (and worked out the mechanics) of a subscription model for ebooks with their wildly successful Safari program for the past several years.

In the past week, Publishing Perspectives offered up a thoughtful piece by Javier Celaya speculating on a free subscription, ad-supported model for ebooks like Spotify is for the music business. PP’s editor, Ed Nawotka extended the speculation to a model of piecework sales: buying a book in chunks or chapters.

Neither of those is what I have in mind. This piece by John Konczal, building on what’s being done in the textbook business, comes closer.

We’ve reached the point where Amazon with their Kindle and B&N with their Nook are perfectly positioned to make a subscription offer. Publishers will have mixed feelings about it and the agents for the top-selling authors have good reasons to be against it, but the proposition seems (to me) to be one that will be compelling to many consumers and will offer tremendous advantages to the retailer that offers it. In fact, I’m a bit surprised it hasn’t happened already.

Here’s how I imagine it working.

The retailer creates a pool of content that will be offered through the subscription service. The proposition to the consumer will be that for a price (let’s say: $50 a month), they can read all they want from the content pool. In turn, the retailer divides 70% of that money (or 75% or 80%) among the publishers in proportion to how many “pages” (a somewhat arbitrary but internally consistent measure) of their material have been read. Of course, all available public domain content will be in the pool.

I am guessing that a very high proportion of the owners of self-published and small press books will find the proposition attractive from the beginning. How the big publishers would react is less certain. My belief is that the smart ones will try it: put in some titles, perhaps from their deep backlist, to get some visibility as to how the program would work.

Meanwhile, the consumers who do this will determine the course of events from there. It seems possible that the impact of this offer will be similar to the impact of the e-ink readers: the heaviest book consumers will see the greatest financial merit in the proposition. And just like customers for Amazon Prime (one annual fee for shipping) and Kindle or Nook owners are highly resistant to buying outside those programs, customers for this subscription service would largely be lost to other book consumption. It will take a more powerful desire to read any one particular book to make it a purchase outside the subscription than it takes to buy it now.

So that, in turn, will drive more books into the program. Authors, and therefore their agents, won’t want to be left out. The early entrants to the program will reap a relative bonanza because they’re on a shelf with less competition which will drive further expansion of the title base.

The tricky part here is setting the right price. As I was thinking about this piece, a reader pointed out a conversation on the Internet about this subject from a different perspective. Here the question was: “what would you pay to read any book anytime you want?” The bidding seemed to begin at about $100 a month. That strikes me as high, particularly since the pool of titles would certainly lack most high-profile books, at least in the beginning.

But a retailer setting the price too low could cost itself a lot of money. Lots of heavy readers spend more than $40 or $50 a month buying books now and, of course, they’d be the first ones to enter such a program (to save money). The benefit for the retailer would be that those customers would be “locked in” to the service, not buying anything elsewhere.

Of course, this idea runs totally afoul of agency pricing. The publishers who are using agency will have the hardest time even experimenting with such a subscription program. On the other hand, if the subscriber base becomes large enough, it will force some reconsideration.

There are all sorts of wrinkles one can imagine beyond this initial idea. There could be a “premium” subscription that had the higher-profile books, creating a more robust revenue pool for them. There could be “vertical” subscriptions for genres or topics. There could be a special discount for subscribers to purchase books not in the pool (except for agency books, of course, whose terms would not allow it.) And a company like Harlequin or a sci-fi imprint of a major house could create their own in-house pool that might attract subscribers. (In fact, the innovative small sci-fi publisher, Baen Books, already has a subscription service!)

But with ebook consumption now climbing rapidly toward half or more of the sales for many titles, it seems inevitable that models that won’t require a transaction for each and every book must emerge. I’d be a bit amazed if conversations about an idea like this, or something like it, aren’t taking place inside the biggest ebook retail shops already.

We created a “thinking about the future” panel for both of our upcoming Publishers Launch shows. They will entertain the subscription question, among other issues, with an eye to the special complexities of international implementation. At our eBooks Go Global show aimed at international visitors and their trading partners at BEA, the panel will feature Tracey Armstrong, the CEO of Copyright Clearance Center; publishers Ricky Cavallero of Mondadori and Cyrus Kharadi of Random House; and agent Simon Lipskar of Writers House. This panel of four incredibly sharp and thoughtful people, moderated by Ed Nawotka, the editor of Publishing Perspectives, represents a real diversity of viewpoints and will explore the practical barriers to this and other innovations across international markets.