One key hurdle in the U.S. market is that most mobile users don't want to pay extra for content, said Joshua Spanier, director of communication strategy at Goodby, Silverstein & Partners. "American consumers aren't prepared to pay for anything. They want it all free," he said, in contrast to Asian and European cell customers.

He added, however, that the new $100 unlimited calling plans announced by the major wireless carriers--especially Sprint's, which includes mobile data--could help to accelerate mobile media adoption.

Others on the panel disagreed, saying consumers were willing to pay for mobile content that was convenient and compelling. "If you deliver value on the content and the service, people will want to pay for that service," said Michael Boyd, vice president of customer insights, advertising and licensing at MediaFLO USA. MediaFLO's mobile broadcast technology powers Verizon's V Cast mobile TV service, which costs subscribers an extra $15 per month.

While Boyd wouldn't disclose V Cast subscribers, he said MediaFLO was pleased with the uptake and customer satisfaction of those signed up. He noted that David Letterman's and Conan O'Brien's talk shows, among others, were drawing surprisingly large audiences on mobile devices during lunch hour. "It's a very popular genre," he said.

But if the pay wall is a barrier to broader adoption of mobile content, the mass audience hasn't materialized yet to make mobile advertising an attractive alternative either. "From a marketing perspective, we are not yet able to make really interesting or engaging mobile experiences on mobile devices," Spanier said. "We're still several years away from that."

He said it would take some kind of "killer app" to do for mobile what the landmark BMW Films campaign did for online marketing back in 2001. "That's yet to really happen, but I'm looking forward to when it does," he said.

Salil Dalvi, general manager of wireless for NBC Universal, was somewhat more optimistic, discussing the success of interactive mobile initiatives the network has created around shows such as "Project Runway." But he acknowledged that luring TV viewers over to mobile screens will take time. "You pick viewers off a few thousand at time, not millions in one fell swoop," he said.

Content providers such as NBC first have to help educate consumers about the full potential of mobile media before the audience grows to critical mass. "We have shown as a company we can bring lots of people to TV, the Web and other platforms," he said. "Mobile is still in a very early stage where consumers are not that familiar with how to view shows or interact with mobile content."

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