The only differance I can see, between rcording a record to a "metal biased 90 or 120 min" (that was the schnizzel partnered with "virgin vynal") casset and trading it to your buddy for stuff he has is that with computers and internet its world wide and instant.
The bands already mentioned owe A LOT to music free trade. It was called the underground. And yes Metallica were jack holes when they went after Napster. Heck with out the HUGE underground bootlegs of their shows,, they would have taken a lot longer to make it. and maybe still playing dives.
“Find your own sound. Dont be a second rateYngwie Malmsteen be a first rate you”
– George Lynch 2013 (Dokken, Lynchmob, KXM, Tooth & Nail etc....)