For all of his fame, Kasseem “Swizz Beatz” Dean is enigmatic as he is ubiquitous. Yes, we know that his wife is superstar Alicia Keys and the 33-year-old’s music is all over the radio and probably your iPod too. In fact, his image, in TV and print ads, helped bring...

Skilled orators are savvy marketers by definition. Take for instance, Shawn “Jay-Z” Carter. The rapper-turned-businessman can deem a product cool or passé simply by how he flips it in a verse. But does Jay-Z co-signing a brand in rhyme necessarily equal a boost in its respective sales?...