If things had gone differently, O'Leary could have made a pretty penny with Ring's pending exit. Still, O'Leary says the offer he made that day was the right one.
"I liked him a lot. I thought he was a great sales guy, but at that time his valuation was insane," O'Leary tells CNBC Make It Wednesday. "It wasn't worth $7 million."
O'Leary says that Siminoff didn't like the offer because "he didn't want to be $700,000 in debt, but it was the only way to structure it," O'Leary continues. "We were both frustrated, which is what happens, because that pitch was actually over an hour long. And I was the only guy that offered anything."
But O'Leary isn't worried about missing the deal. For him, doubting past decisions isn't helpful.
"I never think about it a second time, I really don't," he explains. "I feel that the road is always going forward. You can't go looking back — you can't second guess yourself. You have to do what you think is right in the moment.... For that time, I made the correct decision."
After all, O'Leary says plenty more great businesses are being created each day. He focuses on that.
"I never cry over spilled milk because I've learned on 'Shark Tank,' over 10 years, I'm going to see 10 great deals right after his, and I did," O'Leary says. "[Ring] won't be the last to sell for $1 billion.... The deals are getting bigger every year."
Just last year, O'Leary himself saw a "Shark Tank" business he'd invested in, Plated, sell to Albertsons for $300 million. The key takeaway from Siminoff's story, O'Leary says, is that it can inspire young entrepreneurs to pursue their dreams and invent new problem-solving products.
He adds, "I'm very happy for him."
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