Sara Blakely credits this habit from her teen years with empowering her to build Spanx

The shapewear and apparel entrepreneur says a Wayne Dyer recording taught her to ignore limits, helping her turn $5,000 into a billion-dollar brand.

Sara Blakely founded the $1.2 billion shapewear and apparel company Spanx with just $5,000 in savings, relying on offbeat marketing methods and a good bit of her own grit. The entrepreneur recently revealed that while working toward her success, she had help: a motivational cassette tape that shaped the way she thought about her future.