Wireless carrier AT&T Wireless, which is working with FOX Broadcasting to provide Short Messaging Service voting for the show -- said that as of mid-April, more than a million SMS messages had been sent to vote on the show's contestants by its subscribers.

Viewers also sent 1.5 million more messages in response to polls, trivia contests and sweepstakes, said the Redmond, Wash. operator. Part of the success came about, certainly, from AT&T Wireless' encouragement of viewers to use the technology by offering a trip to see the show, live, to the sender of the millionth text message.

At any rate, it's good news for AT&T Wireless and the mobile messaging industry at large, which has been keeping a close eye on the show's success. If successful, the SMS voting service could serve to jumpstart widespread use of the technology by U.S. consumers -- who have yet to follow in the steps of their SMS-fanatic European and Asian counterparts. Since carriers keep a portion of the fee that consumers pay for every message, SMS is seen as a way to derive incremental non-voice income on top of airtime plans.

"American Idol has brought text messaging to mainstream America," said Andre Dahan, president of AT&T Wireless Mobile Multimedia Services. "Roughly a third of all customers who participated in American Idol through text messaging had never even sent a text message before. Our venture with FOX has done more to educate the public and get people 'texting' than any marketing activity in this country to date."

"Hundreds of thousands of customers are now texting with American Idol; more than likely, these customers will remain active text messaging users in the future," he added.

The "American Idol" effort hasn't gone unnoticed by AT&T Wireless' rivals. In March, Verizon Wireless called for a simplification of the SMS voting process, by assigning common text messaging service short-codes to nine national and cable networks. The idea would be that the major carriers agree to reserve the same voting codes for the same broadcasters -- that's been a shortcoming for the industry since voting codes (also called shortcodes) differ among wireless carriers.

In addition to the political effort, technology is also being tapped to make text messaging voting easier. Later that month, Mobliss -- the vendor handling the nitty-gritty of the "American Idol" promotion -- launched a similar program for "Nashville Star," USA Networks' country music take on "American Idol." Unlike the "Idol" version, however, users from seven wireless carriers can participate in the voting.

All told, up to 70 million subscribers could participate -- from AT&T Wireless, Cingular, ALLTEL, Nextel, T-Mobile, Western Wireless and Cellular South -- simply by sending an SMS to the code "STAR".

"The move by others in the industry to try and emulate us indicates that they, too, recognize the value we've created for our customers and our business," said AT&T Wireless' Dahan.

AT&T Wireless isn't resting on its laurels yet, though. The company also said it has rolled out a new Multimedia Messaging Service to send weekly pictures of show participants to users -- at the cost of about eighty cents a pop, or roughly eight times' the cost of an SMS. While far fewer consumers have MMS-enabled phones in the U.S., the technology is expected to take off in coming years, and already is finding some early footing in Europe.

In addition, AT&T Wireless' "Idol" effort isn't the only source of good news in the wireless messaging space. Indeed, last month saw the entry of a major business media player into the field, when Forbes.com unveiled its long-awaited "Wireless Alerts" feature, a service that sends out text messages in response to news categories.

Boston-based YellowPepper is providing the technology behind the service, which is geared toward newshounds and portfolio-watchers.

"The launch of our Forbes.com alerts application illustrates the strength of text messaging in America," said YellowPepper Chief Executive Marc Theermann.

Looming uncertainties

But wireless messaging's successes are being marred by increasing worry over abuse. This week, the Federal Trade Commission held an anti-spam workshop in Washington, D.C. On the agenda for the first time is wireless spam -- which some experts said is likely to choke the fledgling industry before it gets going in earnest.

According to the sector's largest trade group, the Cellular Telecommunications and Internet Association, text messaging is used by roughly one out of every five wireless subscribers. Penetration is especially high (almost 50 percent) among the 18- to 25-year-old demographic, which is highly sought-after by advertisers. As a result, the Mobile Marketing Association pegs wireless ads to rake in $8 billion annually within two years.

Panelists at the FTC workshop said that ballooning audience could lead to a corresponding rise in spam -- similar to the epidemic of unsolicited commercial e-mail cluttering consumers' inboxes and cutting into the effectiveness of legitimate e-mail marketing.

Jiro Murayama, a manager at Japan's wireless Internet giant NTT DoCoMo, painted a picture of how the future might look if wireless spam continues unabated in the U.S.: he said that DoCoMo has seen days during which 150 million pieces of spam were transmitted over its networks -- to a subscriber base of 38 million.

Episodes like that have lead to the ramping-up of a technology arms race between DoCoMo and spammers, and to the establishment of important new legislation in Japan aimed at curbing spam. Still, he said that despite the company and the country's best efforts, about a third of DoCoMo's users receive up to five wireless spam messages daily.

Christopher Saunders is managing editor of InstantMessagingPlanet.com.