CNET’s Greg Sandoval has a nice look into Sony Music’s sinking digital market share. But he left out one important thing: The company’s total market share — not just digital — has taken a beating since the Sony and BMG merger.

As I have written many times, the company has given up market share since the merger, mostly to Universal Music Group and Warner Music Group. There are a number of reasons, mainly A&R and management (the rootkit problem had no detectable impact on U.S. album market share).

Here’s what I wrote in October 2007:

The Sony BMG merger was completed on August 5, 2004. The week before the merger, Sony’s market share was 13.76% and BMG’s share was 16.02%. The pre-merger combined album market share was 29.78%.Six months later in February 2005, before any of the control and operational benefits would normally have time to kick in, Sony BMG’s market share had dropped to 26.45%. Remember that the combined company had some integration problems.

Six months after that, in August of 2005, Sony BMG’s album market share had dropped to 25.66%. By Christmas 2006, its share has dropped to 25.32%. (Note that very slight drop between August 2005 and December 2006. If you believe the company’s rootkit problem hurt its market share, think again. Sony BMG’s rootkit fiasco hit in November 2005 and appears to have had a negligible impact on market position.)

Sony BMG’s current album market share is 21.76%. Again, the pre-merger combined share was 29.78%, a full eight points higher than where it stands today. Indies have gone from 17.58% in August 2004 to 20.55% today.

Posted by: Amy Sikkes