Get to Know 'Shark Tank' Star Barbara Corcoran on 'Real Biz with Rebecca Jarvis'

— -- Barbara Corcoran is sizing you up. From the moment you step onto the "Shark Tank" stage, she’s sitting back, watching exactly what you do, deciding her next move.

The self-proclaimed “dumb kid” in grade school, who grew up with nine siblings, had worked 22 jobs by the time she was 23, when she took a $1,000 loan, eventually growing it into a multi-billion real estate company, The Corcoran Group.

How did she do it?

“I think the most important thing is I picked good people,” she tells ABC News' Chief Business & Economics Correspondent, Rebecca Jarvis. “And I know that sounds trite, who doesn’t want good people? But I think I have always had a very good sense of who is a winner and who is a loser, I think my only gift is really, I am very good at sizing up people.”

Corcoran says that choosing the right people doesn’t mean choosing the fanciest pedigree, or checking off boxes. Instead, to her, it is determining how someone will react when the chips are down. Will they thrive in the face of rejection, or fold?

“Three days before I was going to be on 'Shark Tank,' I got a call from the production company saying that they decided on another woman,” she says.

Corcoran sprang into action: “I wrote the best email of my life to Mark [Burnett], telling him that I considered his rejection a lucky charm and everything in my life happened on the heels of rejection and that I am really good at rejection. And I think he should invite both women out to compete for the seat, and that is exactly what he did.”

With "Shark Tank" now in its seventh season, Corcoran has invested her own money into 38 companies. If you’re hoping to be her next investment, careful what you do when you step out onto that "Shark Tank" set.

“The show doesn’t tell them that they are going to be made to wait for five minutes before they can speak up,” she says. “They are looking at the Sharks, making great eye contact. Acting really cocky. And then little by little, you see them unwind because no one has told them to talk. And I just watch how they handle that pressure.”

It’s a strategy that’s paid off. Corcoran has a net worth of $45 million and has even written a book, Shark Tales, about her experience on the show. Her other book, If You Don’t Have Big Breasts, Put Ribbons on Your Pigtails, has become a national best-seller, and Corcoran has recently endorsed the company Zebit, which bills itself as "a free financial wellness benefit which provides access to no-cost credit, financial wellness tools." Her endorsement was pegged to the month of March as Financial Stress Awareness Month.

Corcoran says she’s no stranger to feeling pressure or stress, but instead of shying away from opportunity: “I demand what I want. I say what I think. I tell this guy to shut up. And I get the floor. And you want to know something that’s most of it. Just taking the space for yourself. And thinking you are going to get it.”