I just read an article in Time about the music industry. The part about how stolen music often foments the legitimate purchase of music really rang true to me. I believe now that music sharing regardless of its legality can play an important role in marketing music. I believe that current marketing methods will soon be obsolete.
I've come up with a great term for the phenomenon whereby something isn't marketed by traditional means, but relies on its own illegal distribution to generate buzz: black marketing.