Entrepreneurs should think of OPM - other people's money, said Intense Debate CEO Tom Keller, who shared his lessons and advice to entrepreneurs in this interview. "It's important to get other people to buy into the dream," he said. Importantly, Tom isn't just referring to investors. He's referring to customers and vendors.

Paying customers are a form of non-diluted financing. And, vendors can also buy into your vision and help your company if you can work out deals where they loan you equipment or exchange services for free. 

"If you never get OPM, you're probably being quixotic," said Tom. 

Another salient point Tom made was the one about the emotional swings every startup CEO experiences.

"It's a roller coaster," he said. "The highs are high; the lows are low; they're unpredictable when and where they come."

Tom shared a story about a friend who was at a low point after losing a big customer, but immediately perked up upon winning Microsoft soon after. "He went into the dumps and out the world in an hour," he recalled.

As noted in Richard Rosenblatt's video, in which he gives his three pieces of advice, Tom's roller coaster experience is very common among entrepreneurs. Richard said he often feels like he's on the brink of greatness and the brink of complete failure. 

Chris Larsen, who founded E-Loan and Prosper, pointed out that your stress level will be tested. "One day it'll feel like you're taken out to be executed, only to be released moments later to have a spectacular banquet in your favor," he said in his "Lessons learned" video.

Blake Krikorian, who founded Sling Media, said "It's a roller coaster... At 10 in the morning you'll feel the world is crashing around you, but by 1 o'clock, if you have the right attitude, you'll flip over again."

Lessons learned from Richard, Chris and Blake are below.