I remember back in the early 90s I think on the internet when it was only accessible via my university, reading on a newsgroup about how people traded bootlegs from various concerts. People would mail cassette tapes around the country and would use double cassette recorders to make a copy of their bootleg and mail it back to people. It was definitely a different time
They called 'em Tape Trees, way back then, which begat ETree.org
Late 90s there were some great IRC channels for this. I was pretty active in one that revolved around a genre that I most enjoyed.
There was lots of "tape trading" back then. Video too. Foreign TV shows, regional programming, etc. If not technically Internet material, i think this is certainly in the spirit of the Internet Archive.
https://en.wikipedia.org/wiki/Tape_trading