For most agents, scoring that first listing is the golden ticket to breaking into the sales game. But Barbara Corcoran ain’t most agents.

In a wide-ranging recent interview for NPR’s “How I Built This” podcast, the founder of the Corcoran Group and star of “Shark Tank” recounted how she built her firm into a New York City powerhouse. Her start in the business involves a swashbuckling boyfriend with a Lincoln Continental, a “dungeon” of a rental listing, and many more tales of grit and hustle. But perhaps the most fascinating nugget is the tale of how she transitioned into the lucrative sales business.

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Corcoran had started hitting her stride in the rental game when she got referred a young engineer client. By then, she had already honed the art of fending off competition by tying her clients up for the whole day.

“I had learned by then in sales if you could control someone’s time, they can’t go to anyone else,” Corcoran said. “I would say, ‘I’ll pick you up at the Drake Hotel’ – it’s now a new name – ‘at 9 o’clock. And be aware, we won’t be finished till at least 5:30.’”

She showed this engineer two rental apartments, at which point he asked when he could see units that were actually for sale. Of course, she didn’t actually have access to any sales listings.

“He said, ‘well, when am I going to see the ones for sale?’” she recalled. “I said, ‘oh, no, these are for rent.’ He said, ‘no, I want to buy something.’ I was like, oh, crap. So I said, ‘well, that’s excellent.’”

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“So I said I was going to take him on a tour of all New York ’cause it was very important for him to learn all the neighborhoods to see what he could choose from to see what he reacted to best, and that the next day we would show him the sale apartments. Of course, I had no sale apartments. So I got him in a taxi, walked him around every street, showed him every place in town. And then that night, I went home and I hit the floor running.”

Corcoran scrambled to reach out to every For-Sale-By-Owner listing. She recalls telling the owners: “‘He’s Looking Exactly For Your Apartment On Sutton Place. He’s looking for a small terrace.’ I’d read him the ad back and then go ‘but he must see it tomorrow.’ And I booked everything that night. And the third apartment we saw, he bought the next day.”

That commission check allowed Corcoran to hire her first two sales agents. You know the rest.