Facebook's first intern just landed $50 million from Peter Thiel and other investors

Darian Shirazi started his career at 15 years old, when he made his name reselling computer components on eBay. His sales were so impressive that eBay ended up offering him an internship for the next two summers.

Soon, Shirazi was able to build some strong connections in the Valley, and got himself hired as Facebook's first-ever intern when there were just about 12 total employees. He worked directly under Facebook CEO Mark Zuckerberg for nearly two years before pulling himself out to go to college.

His time at Facebook landed him more money than most 20-somethings could ever imagine, but Shirazi didn't stop there. He went on to launch a startup called Fwix, a hyperlocal news aggregator that crawled the web for local news and related content, building up a database that media companies could use to generate leads.

The company saw good traction early on, and in 2011, even got a $35 million acquisition offer from Google. Most 24-year olds would have taken the money in a beat, but Shirazi saw a bigger opportunity there.

"I felt as though if [Fwix] was good enough for Google, it's probably good enough to build something independent," Shirazi told Business Insider. "Of course, I was afraid [to decline the offer] but it was worth the risk. The juice was worth the squeeze."

After turning down Google, Shirazi pivoted his company to target all kinds of businesses instead of just media companies, turning it into a predictive marketing software company called Radius. Its software looks at millions of data signals to identify potential customers, while helping run marketing campaigns to acquire them and analyze their performance.

In the three years since its pivot, Radius has grown into one of the more popular marketing software companies, drawing top Valley investors. And on Wednesday, it announced a fresh $50 million round led by Peter Thiel's Founders Fund, joined by Jerry Yang's AME Cloud Ventures, Formation 8, and Salesforce Ventures.

Shirazi declined to disclose the valuation of his company, only saying it's between $500 million and $1 billion. He did say Radius's revenue has grown 400% in the past 12 months, doubling its valuation, which explains why the company was able to raise again just 10 months after its $54 million Series C round in September. Radius has raised a total of $125 million to date.

Shirazi said most of the money will be spent on ramping up his sales team, as he plans to make a stronger push towards more Fortune 500 companies to use his product. Shirazi hopes these efforts will lead to a wider deployment, and ultimately a bigger company.

"We want to become the de facto marketing platform for CMOs," he said. "I want to build a company that's going to be here forever."