Let me be clear: though the Kindle has some advantages over traditional books, for the moment, I’d stick with the low-tech option. The problem is that the Kindle tries to compete too directly with paper. It attempts to electronically mimic the experience of reading a book. But the book is very, very good at providing the experience of reading a book. In this way, the Kindle occasionally comes off as if Ford, failing to make the conceptual leap to the car, had instead built a motorized horse. Sure, there would be some advantages: the robo-steed would never grow tired, and could be outfitted with more plush seating. But horses are pretty good at being horses. And books, like horses, have evolved to maximize their advantages.

The true promise of the Kindle, and its inevitable descendants, is in creating a product that goes where the book cannot. Printed text is fundamentally limited. Once on the page, nothing more can be done with it. With digital text, everything is a draft, to be edited, altered, broadened, remixed, and redirected. As better conveyors of electronic text are developed, the big question is how content itself will change to take advantage of the new opportunities.

Hyperlinking provides a useful example of how this can work. There is nothing simpler or more fundamental to online writing than coding text so that clicking on it directs the reader elsewhere. Previously, text was a closed container, reliant solely on the strength of its prose and the credibility of its author. With links, text is an open conversation. A study can be described, and interested readers can click to access the original paper. A speech can be quoted, even condensed, with the full version available to any who want it. An argument can be summarized, and the reader can click through to see whether the claims are being represented fairly. This feature is already used online, of course, but for all its elegant simplicity and obvious worth, it’s not as widely used as one might expect. Compare text written specifically to be read electronically—like that on blogs or Wikipedia—and text that is intended for printed mediums like newspapers or magazines. The electronic mediums produce writing that is far richer in links and sources, far more directly in dialogue with opposing viewpoints. The very fact of writing for an electronic medium changes the content.

The possibilities are endless, and many are obvious. Currently, authors are hampered by the nature of the publishing process. Books are begun years before their publication date, and finished months before they will ever reach readers. A book on electoral politics may be completed in 2007 and released in early 2008, its continued relevance reliant on nothing more concrete than the author’s vision and the vicissitudes of polls. With electronic text, however, the original “book” could be just the first step in an ongoing relationship between author and reader. In the most simple form, the book could be updated with new chapters and commentary. Corrections could be downloaded automatically, as could new pieces of supporting evidence. Debates could be held with critics, and the transcripts e-mailed out to all who purchased the original title. The book could be released in 2008, and updated through the election and even beyond, the author routinely applying the insights of the original work to the daily news reports.

This could profoundly alter the relationship between authors and their audiences. One of the finest bloggers around is The Atlantic’s Matthew Yglesias, who’s also the author of the new book Heads in the Sand, an examination of the politics of American foreign policy. Currently, his blog is supported by The Atlantic. But what if readers of his book were offered the opportunity to subscribe to his commentary for $5 a year? Imagine that some thirty thousand copies are sold, and half those readers decide to pay for Yglesias’s further thoughts. That’s now a yearly income of $75,000, flowing directly from readers to author, unmediated by ads or institutions.

Ezra Klein is an associate editor at The American Prospect.