Sudhanshu Sarronwala, CEO of Soundbuzz, which provides music online and via mobile across Asia-Pacific, says the mobile music subscriber base was $250 million in 2006 and $500 million in 2007 and is projected to hit $900 million by 2009.

"Customers are happy to pay a premium for that excerpt of song," says Sarronwala, whose company offers content and hardware for mobile as well as online content. He says the ringtones market has behaved differently in each territory. In India, as mobile penetration grows, each region discovers the next level of ringtones, from monophonic (one tune) to polyphonic (more than one) and truetones (capable of playing full music including lyrics), and so all three co-exist in the same country.

And the biz is attracting quite a few players besides Soundbuzz (recently acquired by Motorola), such as Hungama, the leading aggregator of Indian mobile and digital entertainment content, with 45% of market share. With deals from 16 record labels, 20 studios and many networks, the company offers customers not only ringtones but also mobisodes and games. It has deals with Verizon through its U.S. subsidiary Saavn.

"Demand is not just for music," says Neeraj Roy, m.d. and CEO of Hungama, citing mobisodes and games as his company's other mobile offerings.

However, it is the backbone of his biz. Music labels are eager to sign up with companies like his in order to promote their latest tunes, he says. "Music is the first form of promoting a movie."

Soundbuzz, on the other hand, is building a database including older music and has pacted with labels such as Saregama as well as multiple carriers like Airtel.

And as piracy started eating into Bollywood's music industry, bizzers found a new revenue stream. Roy says only 20% to 25% of the downloaded tunes are illegal because the ringtones are integral to the carrier. "It's a piracy-less market rather than piracy-free," he says.

"If you want to pirate music, you can," Sarronwala says, "but in Asia-Pacific, you have markets where the mobile community is very significant but the PC community is not."

And since the cheapest package sells for just 7 rupees (17¢) plus the cost of the carrier of course consumers spend on impulse. "I like a song, and I want it to reflect the mood I'm in," Roy says.

The ringtone market is not only growing as a way for consumers to express themselves in the ringing of their cell phones but also in the callback tone, which is the tune that callers hear when they dial someone.

"In the U.S. or U.K., there are a million other ways to express yourself, but in Asia this is all the rage," Sarronwala says.