I just want to say: thank you for building one of the most important inventions of our time. (Napster kickstarted the information sharing revolution.)
That said, Napster made it all really easy. They also came along when CD drives were finally commonplace, and Winamp had seeded the ground by having people build up a library of MP3s beforehand.
But its been a while so maybe my rose tinted glasses have munged things a bit! :)
And you're right, BBSes were doing similar things first (although I assume good ones were harder to find than usenet groups or irc chans - don't know because BBSes were before my time!) but of course the mp3 standard didn't exist back when they were at their zenith. MP3s only started appearing en-mass around 1997 I think (??). Before that, I remember every one used to share tiny wav and midi sound file clips on their homepages (my first ever homepage was made to share wav clips of simpsons and monty python dialogue - lol how embarassingly quaint!)
Yeah, in my BBS days I remember downloading MOD files and demo videos. I still remember being blown away by Future Crew.