Spanx founder Sara Blakely a billionaire

The company was valued at an average $1 billion by four different investment banks in recent months, according to Forbes. Blakely's story of how her $5,000 investment turned into a billion dollar business is on the cover of the magazine's March 26 issue.

Though it is too early to determine what impact her new status might have on her professional profile, on Thursday Blakely was swamped with well wishes from friends and customers. "I have been so pleased to know how excited all of my customers have been for me," said Blakely by phone. "It has been so private. It is not something that I have even discussed with my closest friends."

But public recognition of the company's value brings a certain level of validation, giving Spanx -- and Atlanta -- long overdue credit, Blakely said.

"Atlanta has been such a supportive community," said Blakely, a Florida native who moved to the city in the late '90s. "If I had launched in New York, I may have gotten lost in the shuffle."

Life as an entrepreneur hasn't been all sunshine and roses, but Blakely learned at an early age not to be beaten down by the challenges. "With every obstacle that has happened to me in my life, my brain immediately says, ‘Where is the hidden blessing?' " Blakely said. "In starting a business and growing a business, everyday is learning how to manage obstacles."

To celebrate like a billionaire, Blakely took her family for dinner at Ocean Grill on Manhattan's Upper West Side. "My brother said all day he was going to order the lobster," she said. "He ordered everything on the menu, including the caviar."