And corporate sponsorships, much less corporate-sponsored showcases? Sorry, DJ Quik wasn't playing any bar mitzvahs in the '90s, much less Wal-Mart Jam 2013. Aside from Sprite and A Tribe Called Quest and a handful of others (mostly liquor sponsorships), corporations didn't want rappers pushing their product. In fact, in the early '90s, companies ran from hip-hop like it stole something (which it probably did). Reasonable Doubt-era Jay Z wasn't a businessman (not that kind at least), or a business, man, and he didn't break bread with Warren Buffett, Jimmy Buffett, or any of those other Buffets from middle America.
Rappers didn't talk about their "brand" or do corporate-sponsored showcases.