According to Nielsen SoundScan, in 2006, the sales of individually downloaded digital tracks are up more than 67% over the same period in 2005, accounting for more than 525 million digital downloads; already 173 million more than 2005's annual total.
In 2006 to date, 54 tracks have sold more than 500,000 units as opposed to only 22 tracks in all of 2005. None reached that sales mark in 2004.
"It is clear that digitally downloaded music is continuing to enjoy tremendous and growing consumer acceptance," said Rob Sisco, President Nielsen Music.
Nielsen SoundScan tracks digital download sales from more than two dozen providers in the U.S. including every major digital music retailer. Nielsen SoundScan data coverage represents more than 95% of the digital music sales market.