90% of the MP3s I have are backups of cds I bought, countless others have prompted me to buy cds. Besides, not all mp3s on P2P are available on CD. It was Linkin Park's unrealeased tracks that introduced me to their music and I later bought both their CDs. Same with Fuel, Drowning Pool (RIP David Wayne Williams), Korn, Rob Zombie, and virtually every CD I've bought in the last year or two have been since I had heard the music already on MP3.