I remember back when I was making music on my computer in 2002-2003, I was sending demos out to any record label that would care about it and burning CD-Rs and most of it just stayed unplayed except for myself and family members for years.
Myspace, soundcloud, youtube, all of that changed the game and made it easier for people to put their own original creations up. Especially myspace, there are and were so many artists, producers, and DJs that owe/owed their careers to myspace.
I remember being on youtube when it started when I was in college at 21...I thought it was awesome...being able to see music videos I hadn't seen in years on there...checking out tracks I hadn't heard in years on there...
it's still awesome in my opinion, I could waste hours on youtube finding new music....