How relentless emailing helped this 25-year-old snare $300,000 from Mark Cuban

Entrepreneurs with hot start-up ideas try each week to catch billionaire investor Mark Cuban's eye on the ABC TV show Shark Tank. Jason Wilk did it at the W Hotel bar.

At the time, Wilk was a 25-year-old former college golfer at Loyola Marymount University in Los Angeles with a start-up that badly needed another backer. Weeks later — after what Wilk admits was "relentless emailing" — the young entrepreneur got a $300,000 check from Cuban.

Cuban ended up hitting it big. His $300,000 investment in 2011 gave him a little more than 20 percent of Wilk's company, recalls the entrepreneur, now 32. Within four years Cuban saw a big return when digital video distributor Zealot Networks plunked down $85 million in cash and stock for the company, AllScreen.

Why did Cuban invest with Wilk?

"I liked the idea, and I wanted to invest in it," says Cuban in an email. "Nothing magical."

Maybe not. But as any Shark Tank contestant can attest, getting Mark Cuban to part with his money isn't always that simple. Yet Wilk seems to have found the right combination of coming up with a killer consumer idea and marrying it with technology to successfully pitch it to Cuban.

Indeed, Cuban's investment in AllScreen was the first of three deals he's done with Wilk in the last seven years. In April, Cuban joined other investors in putting $3 million into Wilk's latest venture, an app called Dave, which helps millennials avoid bank overdrafts with a monthly service that predicts their future expenses and upcoming paychecks.

Cuban also invested $150,000 in 2012 in a company called WriteyBoard that Wilkes co-founded. It sells large rolls of stick-on white material that are a cheap alternative to white boards in classrooms and office buildings around the world.

The two men are also investors in an unaffiliated company, a start-up auto insurance company called Metromile.

So how to make that first breakthrough to someone like Cuban? For Wilk it started with a blog he had written called "Ten Ways to Get Mark Cuban to Fund Your Company."

Here are some of the pearls he recalls.

1. Email him. Cuban is known for doing much of his business by email. In fact, when Wilk first met him at the W Hotel bar, the billionaire was busily giving away his email address to the throng of wannabes crowded around him.

2. Keep the email short, bulleted and to the point. "He said you have a better chance of him responding if the email is structured that way," says Wilk now.

3. You need to make the case why you want Cuban to invest. The entrepreneur points out that the billionaire really wants to know why you think he's the right investor for your venture.

Getting a billionaire to write a check

It helped that Wilk had a burgeoning track record when he first met him at the Hotel W bar after Cuban had spoken at a TechCrunch conference. As a college student, he dropped the notion of becoming a professional golfer to focus on start-ups. Within a year he sold his first effort, a site that sold discounted golf equipment, for $100,000 to a businessman he won't identify.

Wilk was offering Cuban a piece in a site for which he and his longtime technology partner Paras Chitrakar had just scored $17,000 in seed money from the highly regarded Silicon Valley accelerator Y Combinator. The site, which at the time was called 140bets, combined a Twitter-like site with sports betting. The site later changed its name to AllScreen.

The billionaire investor had read Wilk's blog but was still a tough nut to crack at first, recalls the younger entrepreneur. Not surprisingly, he insisted that Wilk email him the details. That prompted a series of emails between the two men before Cuban would open his checkbook.

"Mark is extremely intelligent, so the best thing I did in my emails early on was try to get his take on whatever I was pitching him," Wilk recalls. "He has great ideas, and if you can incorporate them into your business, I would say the higher likelihood he will be excited to invest."

As it turned out, the 140bets sport site ran low on cash and had to pivot to a new business model, recalls Skip Paul, a senior advisor for investment banking firm Centerview Partners who has informally advised Wilk since his college years. Paul also personally invests in Wilk's companies.

Cuban, whose media properties include a movie studio and cable channel, was a key sounding board to help refocus the renamed AllScreen into a site that syndicated content from major media companies to Twitter, Facebook and other sites.

"Mark is a spectacular and generous mentor to Jason," says Paul. "In spite of his high profile and demanding schedule, he is available to Jason when he needs advice and guidance."

Cuban also let the co-founders use his name to open doors and call his contacts at media companies with content to syndicate and to streaming media companies.

But working with Cuban was rigorous. He required Wilk to send him weekly updates and would pepper him with questions by email soon after he had read them. The only time the two men met was at the annual Consumer Electronic Show in Las Vegas, said Wilk, when Cuban would block out an hour for him.

"He doesn't get down in the weeds; he thinks more strategically," Wilk recalled. "But he always had a lot of comments."

Their newest venture together, Dave, could end up being more than just an app to help millennials avoid overdraft changes, says Wilk. In time, he says, Dave could morph from a series of banking services tailored to millennials into a bank dedicated to that age group.

"Like a lot of people my age, I spent most of my college years getting hit by overdraft fees," says Wilk, who says he has already signed up "tens of thousands" of customers, including 1,000 alone over the July Fourth weekend, when Apple featured it on their app store page.

Cuban, who sold his streaming site Broadcast.com to Yahoo in 1999 for $5.7 billion, no doubt is banking that after scoring big with Wilk on AllScreen, he hits another home run with Dave.

"He is a winner," Cuban said in an email. "He understands what it takes to make customers happy. He is a geek who is always looking for better ways to apply technology. That's as good as it gets."

— By Ron Grover, special to CNBC.com