Change is never easy. And when one industry's massive rise ushers in another's decline, the only way forward is to adapt.

The book publishing industry, and the retailers who select and sell millions of stories and educational guides to their readers, are undergoing massive transformation, as smartphones and tablets find their way into the hands of the curious.

One in six Americans now use an electronic device to read books, and one in six were considering buying one within the next six months, according to a study released by Harris Interactive this fall.

And sales of e-books increased 1,040 percent from 2008 to 2010, according to the Association of American Publishers.

"I certainly think that they're already mainstream," said Andrew Savikas, chief executive officer of Safari Books Online. The Sebastopol company is a leader in the e-books industry, carving out a successful business a decade ago by catering to tech-savvy consumers and early adopters.

"What you're seeing now is so exciting. You're seeing a much wider audience," he said.

"At the same time, that doesn't mean that all print products will go away," Savikas added. "There will always be a market for certain types of printed books, but over time that will shift toward books that are valued as artifacts and souvenirs."

In the book publishing industry, e-books are widely expected to generate 50 percent of the industry's revenues within the next five years, according to Publisher's Weekly. Sales of electronic books continue to grow, month after month, while hardcover and paperback books slide.

Rather than bemoan the growth of a product that could chip away at their core business, some independent bookstores and brick-and-mortar publishers are embracing the trend, and adapting their business models to the digital age.

Copperfield's Books quietly launched an e-books business this winter, a move that enables customers to marry the old with the new by walking into the bookstore to check out a book in their hands, and then upload the digital book to their devices.

"At Copperfield's, we're looking at it as an era of opportunity," said Vicki DeArmon, marketing director at Copperfield's. "We'll always be totally married to the printed book. We love the printed book. It's not an either-or proposition."

Copperfield's is now selling Google e-books through its website, one of more than 350 bookstore members of the American Booksellers Association taking advantage of a partnership formed in 2010 between the group of independent booksellers and Google.

The partnership enables the bookstores to act as co-retailers, selling Google e-books to customers through their websites and capturing a share of the revenues.

Readers can download the Google e-books application, or those who use devices that operate on Android or iOS can download "IndieBound Reader," an application that allows them to read e-books purchased through their local independent bookstore.

"Each independent bookstore on their own probably couldn't pay for the technology to make this happen on their websites, but together we have the power to make this work with Google," DeArmon said. "And to make it work for the customer."

E-books purchased through Copperfield's can be read online or on most tablets or smartphones, except for Kindle devices, DeArmon said.

Readers don't have to shun the bookstore browsing experience to enjoy Copperfield's new digital digs. With a smartphone, a reader perusing the latest best-sellers in the store can scan a book's bar code to access reviews and a portal to purchase an electronic copy. For the digitally inclined, Copperfield's will host a "Petting Zoo" in March to teach customers how to upload e-books to various devices.

It's good timing. Nearly 7 million new mobile devices that run on Android or iOS — the operating system for the iPhone, iPad and iPod Touch — were activated on Christmas Day, a 142 percent jump over last year, according to mobile analytics firm Flurry. And an estimated 1 billion mobile applications were downloaded worldwide between then and New Year's Day.

"There's just this diverse ecosystem emerging for digital reading," Savikas said. Beyond providing a conduit to read, a device like an iPad can serve as bookstore, music player, theater and arcade, Savikas added.

"It's open 24 hours a day, and it's with your customer wherever they are. That's a fantastic opportunity," Savikas said. "The sophistication of mobile devices and the sophistication of services available on them is feeding itself, and really generating a significant ecosystem of opportunity."

E-book sales are expected to reach nearly $10 billion worldwide each year by 2016, according to a December report by Juniper Research, up from $3.2 billion this year.

Savikas did not disclose the annual revenues of Safari Books Online, but said the figure has grown 40 percent per year since the company's launch in 2001. Technology publishers O'Reilly Media Inc. and Pearson Education formed the company, which offers a subscription service to a "cloud library" of digital books. What started as a collection of works by two publishers grew to offerings from 60 publishers with 17,000 available e-books.

The most popular items at the moment are instructional books on HTML5, Android and iPhone application development, Savikas said.

Early in the establishment of e-books, the founders of Safari Books Online carved out a niche catering to customers that were already comfortable reading on the computer. Reference materials for the technology field were a good candidate, because the digital files could be easily searched and updated.

Now, the company has more than 47,000 individual subscribers who pay about $43 a month or $473 per year for unlimited access to the digital library. Limited access to the collection is less expensive. And the product offerings are expanding, with how-to books about soft skills like project management joining the offerings.

About 30 percent of Safari's customers are based outside the U.S., Savikas said, and the company aims to expand its presence abroad.

It's a trend that will expand the reach of information, he believes, just as the invention of the printing press made books available to more readers than hand-written manuscripts.

"The publishing industry historically has been defined by geographic boundaries," Savikas said. "A lot of it has to do with limitations of physical markets . . . electronically, those borders really melt away."