CHICAGO — R U 1 of the 44% of US ppl who txt msg?

If not, Verizon Wireless and Chicago's Vibes Media want that to change.

Building on the strong gains of text messaging in the United States, which nearly doubled in the past two years, Verizon has launched a text-based adventure game to entice customers to buy more-pricey content, such as ringtones and songs.

It's the latest experiment in mobile-phone tie-ins that have proven to be a successful way to engage viewers of shows like "American Idol" and "Deal or No Deal."

Cingular Wireless recorded 64.5 million text messages sent during the most recent season of "American Idol." Those totals include votes, trivia and sweepstakes offers. In 2005, 41.5 million texts were recorded for the hit talent show, up from 13.5 million in 2004 and 7.5 million in 2003.

It's a language younger people know how to speak.

"I religiously send text messages," said Ross Mash, a 26-year-old Chicago entrepreneur. He uses texts to chat with his 14-year-old twin sisters, business associates and friends — and even to flirt.

"You don't have to have a complete conversation with texting," said Gina Glembin, 21, a student at the University of Wisconsin-Milwaukee. "You can just get what you want to know. If I need to have a conversation, I use my house phone."

Mash and Glembin are among the 44 percent of Americans with mobile phones who use text-messaging services, the vast majority of them young adults and teens.

But far fewer buy other content, like songs.

Carriers get roughly 10 percent of their revenue from data services, said Julie Ask, an analyst with JupiterResearch. Ask said nearly half of mobile-phone users send text messages, but only 5 percent of wireless customers have downloaded a game or a ringtone.

Data services contributed $1.13 billion in additional revenue in 2005 for Verizon, with the bulk of activity coming from text messaging. In 2004, Verizon customers received 10 billion text messages, and that number jumped to 21.5 billion last year.

On the other hand, the number of mobile downloads, such as songs or ringtones, didn't grow nearly as much, reaching 139 million last year, up from 100 million in 2004. Yet songs and ringtones, which can cost $1.99, are more profitable than text messages, which cost 10 cents to send.

Hence, carriers are turning to companies like Vibes to extract additional data revenue from customers in new ways.

Verizon is encouraged that text-based promotions can draw new users. In a recent promotion tied to the prime-time game show "Deal or No Deal," Oberholzer said, a different set of its customers interacted with the game. "We got a lot of subscribers to participate who didn't do so before," he said.

For Vibes, the game promotion is the latest in a series of significant deals. It also provides text services for radio stations, concert venues and television shows.

"The idea for the game was hatched from old adventure novels," said Alex Campbell, co-founder and chief executive. More than a year in development, the game includes 562 unique messages. "It's practically a novel-worth of content," he said.