When Amazon launched its new Cloud Drive a few weeks ago, it prompted a debate in the ReadWriteWeb editorial room about whether or not the future of music involved downloads and ownership - as supported by Amazon's cloud stage - or streaming and subscription - as provided by any number of music startups, like Rdio and Spotify. The ReadWriteWeb writers kept our discussion focused on music, but the debate could easily extend to any number of digital media now in Amazon's catalogue: movies, magazines, books.

We're familiar with these streaming and subscription services when it comes to music and movies (Netflix, Hulu for example). But books? Will we (can we) rent books?

Lit Subscriptions and Banner-Ad Books?

A Spanish startup called 24symbols is launching this summer with the promise to do just that: provide a subscription service and become the "Spotify for e-books." (Much like Spotify, 24symbols won't be available at launch in the U.S.)

24symbols will offer an ad-supported and a subscription-based access to e-books, the latter running about 10€ per month. The books are all DRM-free, but 24symbols is entirely cloud-based. In other words, books are streamed, not downloaded for reading.

While we can probably wrap our reads around a Netflix or Spotify for e-books, that bit about ads in our literature might be anethema to many. I mean, how dare they! I poked around on the 24symbols website, but I don't see examples of how those ads will appear. Flashing banners in the margins just won't do, and it will be interesting to see how 24symbols - now in beta - will actually look.

What's on the 24symbols Bookshelf?

As Booksprung notes in its review of the new service, one of the most interesting things about 24symbols isn't simply that it's offering books by subscription. It's how it's splitting the revenue. On some levels, it's actually adopting the funding model that fuels much of the Internet: pageviews: "The company says it will create a standard page measurement as a specific number of words, and apply that to all texts equally when splitting up ad and subscription revenue."

As the reading is all done online, 24symbols will have some fascinating data about readership -- like, at what point in a novel do people just chuck it aside. It's not clear that all of that information will be shared with authors and publishers, but data about page views will serve in part to determine revenue share.

Will this ad-supported, pageview oriented model help keep content farms out of e-books? After all, it would be difficult to make much money with your spammy, scammy e-books if people don't get past the opening paragraph.

The content farms may steer clear of 24symbols, then, but will book publishers join? That may be the thing to watch, for as GigaOm's Michael Wolf suggests, publishers may be better served by a Hulu for e-books, where they set the terms of the publications.

Book Buyer or Book Subscriber? What About Loans? (What About Libraries?)

E-book subscriptions may sound like a new and exciting model for readers, authors, and the publishing industry. But there's already an "all-you-can-eat" model for books: libraries. That library card gets you access to all the books you want, for free.

Libraries are already finding themselves at odds with some publishers when it comes to e-books - not notably HarperCollins with its 26 checkout limit. If a new model for the publishing industry becomes a subscription-based one, how will library loans fit in?

It will be interesting to watch the launch of 24symbols this summer and to see which publishers and authors play along and how many customers are interested. As my ReadWriteWeb colleagues and I debated with the launch of the Amazon Cloud Drive - we may be moving away from the idea of "owning" our digital content. Will e-books be the next content that we subscribe to and stream?