Dr. Dre has tripled his net worth in the past few days. Last week news emerged that HTC was buying a 51 percent stake in the headphone company Dre co-owns with Interscope chief Jimmy Iovine for a startling $300 million, a deal that could eventually push the rapper's wealth north of half a billion according to Forbes' back-of-the-envelope calculations. Dr. Dre has been in the headphone business for less than four years, a little less than half the amount of time he's been working on his final album, Detox, due out next year. But Dr. Dre's not the only hip-hop artist inverting roles. The past few years have seen some of the industries biggest entainers become wildly wealthy off of everything except actually entertaining people.

Sean Combs and Sean John - The notoriously entrepreneurial artist formerly known as Puff Daddy, P. Diddy and just Diddy made his name(s) producing Top 40 smash hits with Notorious B.I.G., but he made his money manufacturing menswear. Launched in 1998, Diddy's Sean John is an award-winning clothing company that's helped Combs become the richest rapper in the world. Along with his record business and stake in Ciroc vodka, Sean John has helped Combs build a $475 million fortune. "My brand is rocket fuel. It would take this brand 10 years to get to where I can take it in one year," Combs told The New York Times in 2008. "I've gotten to the point where I don’t want to do just endorsements. I want ownership."

Jay-Z and Rocawear - Trailing Combs just slightly, the Brooklyn native is worth about $450 million, almost half of which can be traced back to Jay-Z's fashion line Rocawear. Jay-Z founded the company in 1999 with his Roc-a-fella Records co-founder Damon Dash and after several profitable years sold the brand $204 million in 2007, just a couple of months after an investigation found dog's hair in Rocawear faux fur coats. In the meantime, Jay-Z has built out his empire with ownership stakes in the 40/40 nightclub chain, Carol's Daughter beauty products, and J Hotels, a real estate venture. "My brands are an extension of me," Jay-Z said in a 2009 interview. "They're close to me. It's not like running GM, where there's no emotional attachment."

50 Cent and Vitaminwater - People love to make fun of 50 Cent for owning his own flavor of vitaminwater, but 50 Cent probably loves being rich after he netted an estimated $100 million after Coca-Cola acquired Vitaminwater's parent company glacéau for a record-breaking $4.1 billion in 2007. The rapper developed "Formula 50" with Vitaminwater in 2004 at the height of 50 Cent's rap fame. The company let Fiddy design the flavor, outline how he would promote it and take an undisclosed minority stake in the company. Asked about his relationship with Vitaminwater after the Coke purchase, Fiddy said, "I'm excited about it because they allow my input. I'm more closely associated with VitaminWater than anyone. I'm the Air Jordan of VitaminWater."

Rihanna and Totes - This one is pretty obvious. After her single  "Umbrella" became a smash hit, Rihanna launched her own line of umbrellas with Totes. The umbrella line was just the first of many licensing deals for Barbados-born pop star, who would later promote CoverGirl, J.C. Penney, Nike, Secret, Nokia and the Barbados Tourism Authority. According to The New York Times, "Umbrella" became a "corporate rallying cry" that lead to a new kind of endorsement deal that even let Rihanna have a say in the umbrella design process. "We always want to bring an authentic connection to whatever we do," the pop star told The Times. "It must be sincere and people have to feel that."