When Adam Cheyer started working with computers back in the early 90s, he instinctively knew that the future would involve people interacting with the machines in a more natural way, through some combination of speech and graphic interfaces.
That's why in 1993 Cheyer, who was then working in at the SRI International research lab, built the first prototype of what would one day become Siri, the automated voice assistant on Apple iPhones.
Over two decades, Cheyer built 50 versions of his Siri technology. But it wasn't until the iPhone was released in 2007 that his team saw an imminent opportunity for others to use Siri in a way that would make them money.
Cheyer, with co-founders Dag Kittlaus and Tom Gruber, spent the next couple of years building a commercial version of Siri, and in February 2010, the company he co-founded, Siri, Inc., launched Siri as an app in the Apple store, alongside hundreds of thousands of other apps.
Apparently it stood out, because two to three weeks after launch, Steve Jobs called Cheyer's office, unannounced. He wanted to buy Siri, its technology and Siri, Inc.
Cheyer and the Siri team refused Jobs' first buyout offer. "With no hesitation, we said we were flattered but that we weren't looking to sell at that time," says Cheyer. "We had just raised a new round of funding and had gone through a successful launch. ...[A]n acquisition was just not something we were actively seeking."
But when Jobs came back a few months later, they sold Siri to Apple in April 2010 for more than $200 million, according to reports. For a year and a half, Cheyer worked at Apple to create the version of Siri that now exists on the iPhone.
It wasn't Cheyer's only multimillion-dollar exit: He went on to co-found Viv Labs, an artificial intelligence assistant company, which the South Korean electronics giant Samsung acquired in 2016 for about $215 million, according to reports.
It's safe to say Cheyer is a successful entrepreneur. He's proven that he knows what it takes to build a successful company, and according to the serial founder, it's these four things:
An ambitious idea
"[The idea] needs to be big enough, ambitious enough," Cheyer tells CNBC. It also needs to have a market and "be something that people could need or that you can convince them that they would need," he says.
The right team
To launch a successful start-up, you have to have the right co-founders, says Cheyer. "You cannot do it all by yourself. In order to execute on a company, you really need different skill sets."
There are four essential components, according to Cheyer. Every start-up needs a visionary who can think big; a product development expert who can translate the idea into an actionable to-do list; a marketing expert who can communicate the idea to the world; and of course, people to execute the idea.
"Maybe as a founder you can be one or two of those things, but it's rare you'll find someone who can do all four," says Cheyer. "So you need to find the right people to join you as the core team to take it to market."
Other people's money
"When you're in it, you're so close to it, you're really not a good judge" of how worthy your idea is, says Cheyer. So having to convince other people to give you their money to fund your start-up is a good test, he says.
"It's about execution. And what does execution mean? It means you have a limited amount of time and resources — you have to make the right decisions," says Cheyer.
Steve Jobs famously said: "I'm actually as proud of the things we haven't done as the things I have done. Innovation is saying no to 1,000 things." Cheyer agrees, saying what you say no to is just as important as what you aggressively pursue.
"Every decision you make, when you choose to do something, that means you're choosing not to do many other things," explains Cheyer. "Every decision you make impacts what you end up with and how you get there."