Transcript for 'Shark Tank's' most memorable moments as it launches Season 10
Reporter: It's the American dream, wrapped up for reality TV. I will make you a millionaire. Reporter: A chance to make it big. I'm writing a check. Reporter: Or to crash and burn for all the world to see. I'm out. Reporter: The six judges or sharks hold the fate of the aspiring CEOs in their hands. Many of whom have invested their life savings in their product. You don't even have a company yet. You have a great idea and the shark can use his or her connections to put your idea into reality. Reporter: The show, now in its tenth season, has been successful because people can and do make it big. This is what's great about "Shark tank." You never know what's going to walk through that door. Reporter: Like someone pitching a squatty potty. A simple stool that's been carefully designed that allows the user to squat in a healthy position. Reporter: Shark Laurie Grenier invested $350,000 for a 10% stake in the company. Since then, the company has generated $125 million in revenue. She also struck fold with scrub daddy, this cheerful yet powerful kitchen sponge. I'm known as the daddy of the scrub daddy, the cutest but most high-tech scrubbing tool in the world. Reporter: Inventor Aaron Krause appeared on the show in 2012. Since then, his company has done more than $110 million in sales. Is that still one of the biggest success stories on "Shark tank"? Yes, yes. He's tone amazing. I really -- I don't like it. Because I lost on that deal. Reporter: Oh. But judge Damon John has picked his own winners. Athletic leisure socks engineered to look better, feel better, and with a mission to help those in need. Reporter: Investing in bombs socks, a company that keeps your feet warm and does some good in the world. Yeah, my bombs sock company, every time they sell a sock, they give away a pair to the homeless. Come in. Reporter: Sometimes even a failure on "Shark tank" can mean success down the road. Jamie faced the sharks with his pitch for a smart doorbell, then called door bot, but couldn't land a deal. You looked so sad when you walked out of those doors. I felt so bad for you but you kept going. Yeah, I mean, you know, like anything in life, you have to keep going, and you have to keep persevering. Reporter: Soon his fortunes changed. Being on "Shark tank," the credibility and awareness that it gave the business and the product and everything else really catapulted us and allowed us to really build what we have today. Reporter: Five years later, his smart doorbell, called ring, is a huge success. And he is back as a guest shark. . Reporter: Does it just feel so good to be up there, sitting along with all these other sharks that passed on you and now you're right there with them. Is it going to feel like a little -- I'm not that kind of a person. Yes, it feels great. It really does. It really does. Reporter: And it's almost tenth seasons on the air, the sharks have seen nearly 1,000 hopefuls come through these doors. What is it about the show that you think people keep coming back for? It's the American dream. People want to be successful. Nobody wakes up and says, I want my life to suck. You watch our show and you think, I can do it. Reporter: We spent the day onset. Welcome to the "Shark tank." Reporter: Wow. These are my shark friends. Reporter: Learning the secrets of the show's success. Nice to meet you. Reporter: We found Laurie in her dressing room during a break in their marathon shooting day. At the end of the day, I really like making dreams come true. I know it sounds a little, you know, corny, but I really do. Reporter: The entrepreneurs who appear on the show have just one shot to convince the sharks to invest. The stakes could not be higher. We're here today to ask you for $500,000. $100,000 investment. To make better socks. Eat better. Which one of you will be our soul mate? Reporter: You've got a handful of minutes to either make or break what they feel is their whole career. That one pitch can be excruciating to watch. No fly cone. And you set it over a scooper. My inventions are making over a billion dollars per year. Can you name one? Reporter: What is that one mistake that drives you crazy H? No energy. They get so inside their heads so they're trying to make sure they say the right thing in the right order to get their numbers right and they get so nervous. Do we have a deal? Of course. Reporter: But when an entrepreneur nails it, it's golden. Do it. All right. Got a deal. Good. Awesome. Reporter: The sharks maintain a breakneck shooting schedule. Leaving little time for regrets of deals not done. I'm going to tell you the secret. The minute the pitch is over, if I didn't do it, gone. We shoot a whole season in about four, and so we'll get here in the morning and we'll shoot 10, 11 pitches one after the other. That's why we're in the same clothes all the time. Reporter: You're able to move on. Like an old girlfriend. No rear view mirror in "Shark tank." Yeah. We don't care. Reporter: The show's enduring popularity has surprised even some of the most seasoned executives. I didn't think it would last. I thought, you know what, this is a business show, it was okay, and I'll do my three guest shark episodes. And then all of a sudden, boom. It's crazy how big it's gotten. Reporter: Did you ever expect it to be such a massive success? Yes. Yes. Kevin -- Reporter: Mark said he did not expect it to be. Mark doesn't have the same -- much confidence in himself. Reporter: Even after all these years, "Shark tank" is proof America's entrepreneurial spirit is alive and well. And there's always the future. That's what's so wonderful about "Shark tank." Reporter: For "Nightline," I'm in Los Angeles. Your heart just cheers for those contestants, right? The tenth season of "Shark tank" premiers this Sunday on ABC.
This transcript has been automatically generated and may not be 100% accurate.