At least half of European users of music file-swapping service Napster are prepared to pay for it, though a subscription-based model runs the risk of alienating the youth market, if a new survey can be believed.

The survey, by research firm Jupiter MMXI, came out yesterday - the same day that Napster and the recording industry were set to return to court in California. The Ninth Circuit of the US Court of Appeals recently largely upheld an injunction by Judge Marilyn Hall Patel prohibiting Napster from operating its service.

The survey rated Napster as the thirteenth most-visited website in Europe in January. Napster's European audience is split into two main groups: men under the age of 24, and older men with more disposable income, according to Jupiter. Women accounted for 23 percent of Napster users in Europe.

Should Napster be forced to turn to a subscription-based model in order to survive, older users with more money to spend would not object to paying a monthly fee for the service. But younger, low-income users - considered the heaviest music consumers - would be unlikely to pay for the online service, the survey found.

If Napster failed to keep its service free, Napster's five million European core youth users currently using the service would inevitably be sent to grey-market alternatives such as Gnutellla, "merely sending the problem elsewhere", Jupiter MMXI said.