Internet music users are more likely to download singles than full albums, research has suggested.
Many people download music from the internet
NPD Group tracked useage by both legitimate online music retail stores like iTunes and file-sharing services.
The results suggested that consumers downloading from the web took only one track from an album 85% of the time.
And 94% of the time two or fewer tracks were downloaded from an album, with the entire album being taken from the web less than 1% of the time.
The study suggested that the majority of digital song tracks downloaded by consumers were "catalogue" sales - released more than 18 months ago.
That compares with a roughly 50/50 split between new and catalogue sales in CD market.
Apple's iTunes was launched in May this year
These figures are affected by the fact that digital downloading is still dominated by illegal file swapping, where albums are not as readily available or promoted.
NPD's Russ Crupnick said: "In the world of paid services, consumers may prefer buying singles, so record companies must locate a balance between effectively promoting new releases while not losing sight of the revenue-generating power of popular songs from the catalogue - and import or concert tracks, as well."
He added that it was "sensible" to offer a discount when consumers buy four or five songs from the same artist, regardless of what album they originate from.
"It may not be all about the best-selling songs, either," he said.
"Less popular tracks offered as free downloads might even be effectively leveraged to market paid downloads of more popular songs and drive sales of full CDs."