Although trade book publishers are often criticized for being slow to embrace new technology, a range of houses have been experimenting with ways to sell their digital content. As the projects highlighted here show, early efforts have yielded mixed results, and small sales. According to The Veronis Suhler Stevenson Communications Industry Forecast, digital spending on consumer books totaled only $59 million in 2006, with most of that revenue coming from spending on e-books and digital downloads of spoken-word audio. (Because those two categories are the most established digital distribution formats, they are excluded from this piece.) Still, publishers realize that they must begin to test new and different business models to gain traction in a world where more and more information is moving to the Web. Carolyn Pittis, HarperCollins's senior v-p of global marketing strategy and operations, says, “I don't know a publisher around town who's not experimenting with ways to monetize digital content. It's the main focus. I think 2007 will go down as the year the industry woke up and said, 'Okay, we have to take this seriously.' ”

Yet many questions persist: What are customers willing to pay for? How do they want to receive information? And the $100,000 question: Will digital downloads cut into print book sales? No one knows the answers. But as Allen Noren, director of online marketing at O'Reilly Media, observes, “We're all struggling to remain relevant to our audiences.” Here are some ways publishers are keeping that relevance.

Cell PhonesBrent Lewis, director of Internet and digital at Harlequin, summed up the inherent problem of making books available via cell phone: “Most consumers—in the high 90%—are completely unaware of what their phones can do.” The iPhone is changing things, but in general, there's a “lack of education” when it comes to doing things other than talking and texting. Still, publishers are trying to find ways to distribute content through a device that most people don't leave home without.Mobifusionhttp://www.mobifusion.comWhat it is: Mobifusion partners with publishers (and other media companies) to provide mobile entertainment and information products. Among the publishers that have provided Mobifusion with digital book content to make into mobile products are Avalon, Houghton Mifflin, Meredith, New World Library and Simon & Schuster.Launch date: January 2007What's available: Dozens of nonfiction books in reference, health, travel, religion and spirituality and entertainment, as well as children's.What it costs: Costs vary. Fast Food My Way, a Houghton cookbook by Jacques Pépin, costs $14.95; The World Almanac and Book of Facts 2007 costs $29.95.How it's doing: Chris McKenney, cofounder and chief content officer of Mobifusion (and former COO of Publishers Group West) says there are some challenges: the key is having applications perform on all platforms (there are more than a dozen, as opposed to the computer world, where there are two). And North America is a few years behind many of the hottest markets, such as Korea and parts of Europe.Harlequin on the Go it is: Subscribers receive a small chunk (a few hundred words) of a short story each day. The feature is currently available only to Sprint customers.Launch date: Spring 2006.What's available: 10,000-word stories that were written specifically for digital applications.What it costs: $2.49/monthHow it's doing: Lewis says, “It's been going okay. It's really just experimental for us in the mobile space.” But during a trial period with Verizon, the feature generated several hundred thousand trials.E-mail
Daily Lit
What it is: E-mail and RSS feeds deliver 1,000-word book installments.
Launch date: May 2007
What's available: Books from Globe Pequot, Berlitz, Kaplan, Perseus, Baen, Chronicle and E-Reads
What it costs: New hardcover releases are $9.95; hardcovers from a year or two ago and paperback originals are $6.95; mass market and backlist titles are $4.95; in special cases, books can be less than $4.95 or even free.
How it's doing: Spokesperson Jeff Rutherford says more than 130,000 books have been subscribed to, and DailyLit is approaching 100,000 users.
Customized Books
One of the least high-tech ways publishers are making their content available online is by allowing customers to personalize books. In reference areas such as travel and cooking, publishers are toying with different DIY models that allow customers to pay only for the information they want.
Lonely Planet's Pick & Mix
What it is: Consumers select chapters from Lonely Planet guidebooks to download on any device that accepts PDF files and can mix chapters from different books to create the guidebook they want.
Launch date: July 2007
What's available: Guides to Latin America and the Caribbean.
What it costs: Fees range from $2 to $5 per chapter, depending on length.
How it's doing: Senior digital product manager Tom Hall says Pick & Mix “has exceeded expectations” and “sales of chapters have just about doubled our targets.” And most noteworthy for publishers with an old-school mentality: “There's been no discernible impact on our print guidebook sales, though we're keeping an eye on it, as it's clearly a concern.”
What it is: Visitors create their own printed or digital travel guides by combining guidebook content from DK with other travelers' recommendations and reviews. Customers can add their own cover photo and title.
Launch date: March 2007
What's available: A limited number of cities and countries.
What it costs: A printed 96-page book costs $15, including shipping. A downloadable PDF costs $5.
How it's doing: Publicist Katy Ball says interest is “growing steadily,” but that the feature “hasn't exceeded expectations.”
What it is: Customers build their own cookbooks by choosing recipes from Condé Nast's and having them bound in a hardcover binder with a customizable cover and personal notes next to the recipes.
Launch date: October 2007
What's available: 25,000 recipes from Bon Appétit and Gourmet
What it costs: $34.95 for up to 100 recipes, plus shipping.
How it's doing: It's been less than a month, but CEO Kamran Mohsenin, who cofounded the photo-sharing site Ofoto, now owned by Kodak, says, “People are saying, 'I can't believe no one has done this before. It seems so obvious.' ” It's not clear what TasteBook's long-term plan is, but Mohsenin says he's looking to expand in other areas.
Chapter Sales
O'Reilly Media
What it is: Through its site, computer book publisher O'Reilly sells books by chapters.
Launch date: June 2007
What's available: Approximately 800 titles are in the program, with an additional 200 more to be added. Each chapter has its own navigation and its own table of contents and index. There is no DRM protection, and customers can read chapters online or print them out.
What it costs: Every chapter is $3.99. Allen Noren, director of online marketing, says he wants to keep the pricing simple, although the company may experiment with variable pricing at a later date.
How it's doing: Noren says the program has taken longer to roll out than expected. Chapters that sell best are “obvious chunks” of content, rather than pieces that are part of a whole, Noren says.
Baen's Webscription Service
What it is: Subscribers receive a novel in three monthly installments, beginning three months before the book's publication date. Each month, four titles are available.
Launch date: 1999
What's available: More than 650 novels from Baen Books, Del Rey, Meisha Merlin, SRM Publisher, Subterranean Press and Tor Books.
What it costs: $15
How it's doing: Baen Books publisher Toni Weisskopf says more than 30,000 people have bought books through Webscription.

Laura Dawson, a consultant on publishing technology, contributed to this article.