My insights on this come from a talk that I attended in Halifax the day before I left to move to Toronto (3-4 years ago now). Fingerstyle Don Ross was talking about his music and how he estimated that he lost about $80,000 a year on pirated music. Yes on one side he was happy for the exposure, but on the other he didn't like the poor quality of tracks that were getting out there... and because his demographic might say buy only one of his CDs, the wide-spread availability of his material available online for free squeezed him. His data was based on his CD sales over the course of his 20+ career, and how things had changed over time, when the whole Napster thing happened. Musicians should be able to do is control how their music is dissemenated. I for one am happy that my band's video has been played 1,200 times on youtube, almost a thousand plays on myspace, but those were all my choices to have them available.