I'm saving this whole thread re-reading it over and over again, thanks to Aloisius chiming in (giving a valuable and rare peek at the back-end), and the insight into what drives music discovery.
I do credit Napster for awakening a love for music. My father had a deep record collection from the 60's, and he had mentioned some very hard to find items he's wanted for decades that I found on Napster in couple of hours of searching. This was what made it awesome for me. The ability to browse someone else's collection was an incredibly effective music discovery system, and introduced me to music I'd never have discovered on my own.