Just because you're a celebrity, doesn't mean you can do everything.
Scores of Hollywood stars have tried their hand at designing clothing—including Jennifer Lopez, Eva Longoria, and even Sarah Jessica Parker. Yet despite being popular and incredibly stylish themselves, their fashion lines have been huge fashion fails.
Tracy Taylor, the U.S. Editor of net-a-porter.com states "I almost think it's more difficult for a celebrity to launch a clothing line. Not only are the eyes of the customer on them, but the eyes of this rarified group that almost is unattainable for celebrities and that's to be a fashion designer."
So what makes a fashion line successful? Attention to fine detail, quality of the material, and some serious stylistic editing (this means you, Kanye West!).
Having a huge fan base doesn't hurt either. Just ask Jay-Z.
Nicole Richie, House of Harlow: $2 million

Nicole Richie emerged on the fashion scene in 2007 with jewelry collection House of Harlow 1960. Four years later she introduced her ready-to-wear clothing line, Winter Kate.
While her reps refuse to provide company sales figures, her two lines have already added an additional $3 million to Nicole's overall net worth.
Rachel Zoe: $20 million

While Rachel Zoe may have an unfair advantage given that she is the hottest stylist in Hollywood, her clothing line has proved you can be fashionable and also have a successful clothing empire.
Her clothing label, the Rachel Zoe collection, debuted in 2011 and was an instant success. Her line is set to make $20 million by the end of this year.
Justin Timberlake: $50 million

N'Sync member Justin Timberlake co-founded William Rast with best-friend Trace Ayala back in 2006. Thanks to their well-fitting jeans, their company rakes in an approximate $50 million per year in sales.
See the rest of the story at Business Insider