Digital music download services are exploding, with the number of US consumers downloading tracks doubling in the first half of 2003.

Ownership of MP3 players such as Apple's market leading iPod is also climbing: 19 per cent of US music downloaders own such devices – up from 12 per cent in December 2002.

A quarterly digital music behaviour report from research firm Ipsos-Insight shows that in late June 2003, "roughly" one out of six (16 per cent) of US music downloaders aged 12 and older had paid to download music online. The company says this is the equivalent of 10 million people.

At that time, Apple's iTunes Music Store was setting the trend for digital music sales and consumer rights. Few of the current big-name digital music services, such as Napster 2.0, existed at that time. Forrester Research recently asserted that digital music sales will account for one third of all music sales by 2008.

The data is contained within the company's Tempo: Keeping Pace with Digital Music Behavior, a quarterly research study that examines the ongoing influence and effects of digital music worldwide. Report author Matt Kleinschmit observed: "A twofold increase in the number of American downloaders exposed to for-pay music downloads in just a six-month time frame (compared to 8 per cent in December 2002 and 13 per cent in April 2003) signals a remarkable shift in downloader behaviour."

Wisdom of youth

The research also reveals that young adults aged 18-24 are most likely to have paid to download digital music, however, it also shows that older downloaders are getting involved. 19 per cent of computer users between 25-54 have also paid to buy digital music.

The research also shows that 12-17 year olds – who often don't have credit cards – are the least likely to say they have paid for digital music. Apple has attempted to address this point in iTunes 4.1, introducing gift vouchers and a parent-controlled allowance feature so people in this age group can choose to use its legal service rather than steal music.

Kleinschmit said: "Downloaders of all ages are clearly beginning to experiment with fee-based online music distribution in increasing numbers."

The analyst points out that the new data was collected in June, prior to the debut of iTunes for Windows and competing Windows-friendly services: "It will be interesting to see how these refined fee-based online music services impact this figure in futures waves of Tempo, and whether downloaders' dependence on peer-to-peer filesharing decreases accordingly."

On the increased market-share for MP3 players, Kleinschmit said: "The rise in portable MP3 player ownership among US downloaders, coupled with the growth in paid downloading, suggests that digital music enthusiasts may be shifting their overall music acquisition and listening behaviors from a physical to a digital approach."

He described this as a potentially "positive sign" for associated industries: "Legitimate market opportunities are increasingly prevalent in the world of digital music, even alongside unauthorized peer-to-peer filesharing," he said.

The BBC's North America business correspondent, Stephen Evans, has an opinion piece available that confirms that digital music is transforming the way US citizens listen to music.

LimeWire chief technology officer Greg Bildson recently dismissed the impact of legal services on peer-to-peer networks. Speaking to Macworld he said: "We've seen no effect on the number of software downloads we see in any given day."

Data supporting the Ipsos-Insigh's claims was collected between June 27-30 from a sample of 1,112 respondents aged 12 and over. The analysts claim its conclusions are 95 per cent likely to be accurate.