While the market for print publishing continues to shrink, its digital counterpart is rapidly growing, driven mostly by cell phone users, panelists at a seminar said Thursday.

The vigorous market for cell phone publishing can be attributed to the easy fee-payment process, according to Masahiro Kitagawa, the panel's moderator and executive vice president in charge of group business development at Impress Holdings Inc.

"The market for cell phones increased because the billing system is much simpler," Kitagawa told The Japan Times after the seminar on digital publishing held during the Tokyo International Book Fair at Tokyo Big Sight.

In fiscal 2008, the digital publishing market was estimated at ¥46.4 billion, up ¥10.9 billion from the previous year. The market for cell phone publishing accounted for ¥40.2 billion, up about ¥12 billion, according to Impress Holdings. Digital comic books are selling especially well.

Digital publications for computers, however, fell for the first time, said Kitagawa.

Since the fee is automatically charged to a client's monthly cell phone bill, a user can access mobile Web content without the hassle of going through the billing process.

He added that the improvement in cell phone devices, which now feature larger screens and faster Web access, also contributed to the market's rapid growth.

The mobile digital publishing industry's brisk sales are due in large part to comics for young people as well as adult content, including comics and novels. But some mainstream authors and comic artists are refraining from digitizing their content, Kitagawa said.

Still, the market has become quite steady, and some comic artists have let their content get published digitally in the last year or two, said Osamu Yoshiba, another panelist and director of digital content at major publisher Kodansha Ltd.