Another wrinkle on the mash-ups question: For some folks, myself sometimes included, maybe mash-ups forced a reappraisal of modern pop, meaning Top 40 stuff. Let’s say Strawman A heard e.g. “Genie in a Bottle” or “Smells Like Booty” and then wondered if the C. Aguliera or D. Child songs they’d ignored had as much juice on their own as they did paired w/stuff that was more familiar. They went back and discovered that, in fact, some of them did. So they began paying closer attention to Top 40. In this scenario, mash-ups act as a gateway from indie to pop--not the only gateway, but a decisive one.
I used to sell hologram bolo ties at the Mall of America