It’s been 10 years since electronic books arrived on the scene, enabling readers to download full-length text of best sellers to their personal digital assistants—and these e-books have been quietly gathering a following. Although downloads initially were available only through a Web page, more recently over-the-air downloads to PDAs and smartphones have been offered.

What’s the best selling e-book genre? Conventional logic might suggest something high-tech like science fiction, but that’s a little farther down on the list. The number-one genre, surprisingly, is romance novels.

“Fifty-one per cent of our customers are female,” noted Alex Bloom, general manager of the smartphone business operations at key e-book supplier Motricity. “That’s a very high percentage of females for technology consumption.”

What’s motivating women to read e-books? “A lot have told us they really like digital books so they don’t clutter their home with books,” said Bloom. “If you keep 75 to 100 books on your PC, you can put three to six on your mobile device to take with you whenever you want. And on a mobile device, you can carry multiple books without breaking your back.”

Considering the lurid covers that printed romance novels typically have, there also may be another reason for reading such titles electronically. “Business women in particular who do a lot of traveling may not want to be seen sitting on an airplane reading a romance novel,” Bloom commented.

To use Motricity’s offering, customers download a reader client onto their PC or mobile device, which is available at no charge or in a $9.95 premium version. The reader lets end user customize font size to what is most comfortable for them and also offers automatic or manual scrolling options. Motricity charges the same price for an ebook as the book’s publisher charges for the print version. Book downloads take less than a minute, even over a GSM or CDMA network, said Bloom, who added that the company currently is looking at supporting Blackberry and other devices.

Motricity recently has seen a surge in sales, which it attributes in part to the explosive growth of smartphones. Not surprisingly, the company also has seen an increase in competition. Its most direct competitor is MobiPocket, which was acquired by online bookseller Amazon a couple of years ago. As with Motricity, the MobiPocket offering works with smartphones and PDAs. Amazon also offers a dedicated e-book device, as does Sony.

End users ultimately will prefer to use their smartphones for e-book reading, said Roger Entner, senior vice president of the communications sector for IAG Research. Although a dedicated device might provide a superior reading experience, Entner asked, "On the other hand, how many devices do you want to carry around? And even more importantly, how many do you want to charge?”

Entner said women actually are heavier users of mobile data than many people believe—they just have different preferences in how they use the service. “Women tend to be more wallpaper and ringtones, and men tend to be more browsing and games,” Entner said.