Nielsen Soundscan numbers for the first half of 2006 came out last week and much of the press focused on the upward slope of the digital sales curve and the downward slope of CD sales. Album sales went down from 282.6 million this time last year to 270.6 million for the midpoint of 2006, while downloaded tracks soared 77% to 281 million in the first 26 weeks of 2006.

To make it apples to apples, there's still a big gulf between 271 million physical albums and 14.7 million digital albums (sales of which were up 126%), but the market share of digital music is increasing, from 2.2% last year to 5.2% this year.

I suspect the argument that digital music is cannibalizing CD sales may be simplistic. The CD side of the business has already enjoyed much of the recycling boom that comes when people re-buy old music in an updated format, whereas digital music, which is getting some baby-boomer love, still has that wave to ride.

It's been a bad year for new music, sales of which have dropped to just 22% in the first half of 2005, compared to 39% in the same period last year. If CD sales are indeed more dependent on new music for sales juice than are downloads, then the preceding statistic might explain some of the growth disparity. No, there's not a 50 Cent or Norah Jones to drive sales, but I suspect that the annual trend of fewer and fewer new releases is also playing a role.