The founder of Spanx, Sara Blakely didn't know the first thing about the pantyhose industry (or business for that matter) when she launched her company. She had only one source to operate from: her gut. Blakely believed her invention would help millions of women, and she was right. Her passion and dedication has made her a billionaire. That same passion, along with an added touch of spunk comes through in this interview with former SUCCESS Publisher Darren Hardy.