The U.K. business of online music service Napster has disclosed that it has sold more than 55 million downloaded and streamed full-length tracks since its launch 15 months ago.

The U.K. business of online music service Napster has disclosed that it has sold more than 55 million downloaded and streamed full-length tracks since its launch 15 months ago.

The sales figures, announced today (Sept. 5), are the first released by the company. Napster U.K. also says it has 750,000 registered members that are regular purchasers.

Leanne Sharman, Napster VP and U.K. GM, tells Billboard.biz that the results prove digital music is making a significant contribution to the recording business. "These are all paid for. The more (Napster users) consume, the more record companies get paid."

Citing the results from a poll of 5,000 registered users, Sharman says its online music consumers typically came from a mature demographic. "Our research showed that 80% of our members are more than 25 years old, contradicting some of the received wisdom that online music fans are under 25." Moreover, one-fifth of those questioned said they no longer buy physical CDs.

Despite the increased competition from the established iTunes Music Store, MSN Music and the recently launched HMV Digital and Virgin Digital, Napster U.K. believes it will continue to attract more than 50,000 new members each month thanks to its monthly subscription-based business model.

Napster charges £9.95 ($18.31) a month to download and stream as many songs as they wish from a catalog of 1.6 million tracks. The songs expire when subscription payment stops. The service charges £0.79 ($1.45) for permanent downloads.

Napster has announced plans to launch in Germany and Japan to complement its U.S. and Canadian businesses.