Verizon Wireless sees ringback tones as another way to get a little more incremental revenue out of the oh-so-fickle youth market, with whom ringtones have been so popular in the first place. While ringtones allow subscribers to enjoy their own musical tastes when called, ringback tones foist those tastes upon the people calling them. What could be more fitting for an increasingly exhibitionistic youth segment?

"This goes well beyond the ringtones," said John Harrobin, vice president of marketing and sales for Verizon Wireless's Western region. "Ringtones are a way for you to communicate with yourself. Ringback tones communicate with your callers. They're another way for our subscribers to express themselves to the people they know."

They're also another way for Verizon Wireless to rake in the dough if the service is successful. Unlike ringtones, which are handset-based, ringback tones originate from the network, meaning any subscriber with a postpaid subscription regardless of handset can use the service. A carrier doesn't have to optimize specific tones for certain handsets or manage monophonic, polyphonic or digital recording versions of the same tone. It doesn't have to figure out a way to airlift each tone to each handset. Nor does it have to wend the convoluted road of digital rights management because the intellectual property is stored in the network, not on the phone itself.

On top of that, because the service is network-based, Verizon Wireless can charge a monthly recurring fee of $1 to run the service so the ringback tone keeps paying for itself long after the customer shells out the $2 to buy the tone in the first place.

That proposition has to trigger a Pavlovian reaction in the mouth of any carrier, but so far, Verizon Wireless has been the only one to embrace it. However, Verizon Wireless hasn't quite embraced it completely. It's only launching with gear provided by Asian partner SK Telecom in Sacramento and Southern California, where its youth-focused marketing is particularly acute. But it has committed to a nationwide rollout in 2005, once it irons out its service.

However, it's not just Verizon Wireless that will be monitoring the service in . If Verizon Wireless' trial enjoys an inkling of success, the other carriers are sure to investigate their own ringback tone applications. The carriers are in such competitive lockstep that any first-to-market advantage would be quickly eliminated in 2005, said Brian Demers, vice president and general manager of mobile applications business for NMS Communications, the company providing the core technology in Verizon Wireless' and SK Telecom's launch.

"The other carriers will absolutely launch next year," Demers said. "There had to be a first carrier to launch in the Americas and we're just happy that it was a big one."