The backend servers were linked. If your request couldn't be fulfilled on one, your search was forwarded to the next server. The total number of files on Napster at its peek was over half a billion files. Further, that picture must have been from a server that just started because the average server had significantly more users/files on it.
Further, Napster users were ripping everything in sight. There were mp3 encodings of old wax cylinders uploaded for goodness sakes.
- The discovery on Napster was non-existent. You could browse through a users' collection, the same way you can browse through playlists today.
There was an entire curated music website dedicated to music discovery that loaded into the client.
The chat and instant message system allowed people to talk about music which created a massive music-focused community. It was wildly popular.
And don't underestimate browsing. People would search for the one song they were interested in, notice who they were downloading from, browse the other user and then start pulling down their music if they noticed several songs they liked in it. They then could send a message to that user and add them to a friend's list. That was not just music discovery, but friend discovery as well.
- I am pretty sure it was a substring match
The very first versions were substring match when there were maybe 10,000 users. Later version were not and allowed basic boolean queries like term exclusion.
- Not going to get into speed, because it wasn't Napster's fault, but even back then it was far easier to get music elsewhere other than Napster if possible
There was an algorithm on Napster that did network distance biasing. Basically, if you were an AOL user, you'd first get AOL users back when doing a search. If you were an Internet 2 or even @Home user however, your speeds were epic.
* Note: I built and ran the Napster server.
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.
I miss it.