The massive success of 50 Cent, Kanye West and P Diddy should leave little doubt that rappers are some of the best marketers and businessmen on the planet. Decades before 50 Cent cleared 100 million off Vitamin Water, Run DMC made adidas relevant and revived the stalled career of Aerosmith while leveraging their fan base to crossover to the mainstream. And at the turn of the millennium, independently distributed white rappers like Aesop Rock, El-P and Slug rode the train tracks laid down by the Beastie Boys to re-invent hip-hop and the recording industry, and pocketed six figure incomes while owning 100% of their publishing rights. Jay-Z said it best, “I’m not a businessman, I’m a business … man.” Good advice comes from the…