One e-mail can change everything. If it gets a response from the right person.

After reading a blog post by billionaire Mark Cuban last year, 25-year-old entrepreneur Ryan Ozonian learned that the Dallas Mavericks owner was interested in social gaming. Ozonian, president and founder of Mention Mobile, specialized in that.

At the end of the post, he saw Cuban’s e-mail address. Ozonian was looking for investors. It was late at night in his apartment, and he decided to pitch his company to one of the richest men in America.

“I wrote a really passionate e-mail and attached the pitch packet, sent it to him and I had a response from Mark Cuban in eight minutes,” he said.

Ozonian recalled that he was practically delirious with excitement, but at the same time wondered if the response was really from Cuban. He called his business partner and co-founder, Kory Jones. Jones, 44, looked at the message and agreed it looked legitimate.

“At first I was like there’s no way,” Ozonian admitted. “I didn’t think we’d get a direct response from him.”

But as the e-mails continued back and forth, “I very quickly realized it was him,” Ozonian said. “He agreed to give us our initial $250,000 round of funding to round out our ideas and form a team.”

Mention Mobile specializes in asynchronous games, meaning each player takes turns and can come and go from the game – online chess, for example. The company had produced a game, Trivia Friends, that Cuban had played. The game draws information from players’ Facebook accounts and then forms questions based on what their friends have posted.

The company’s games feature advertising and are offered on a freemium model, which means the basic game is free but players can opt for a deluxe version that costs as little as 99 cents.

Ozonian wouldn’t disclose revenue but said the company is not yet profitable.

Cuban, who made his fortune in telecommunications before buying the Mavericks and is now one of the investors, called sharks, on TV show “Shark Tank,” told the duo he wanted them to work “hardcore startup style,” Ozonian said.

“(Cuban said) I’m not going to give you $5 million, I’m going to give you $250,000 and see what you’re made of,” he said.

When Mention Mobile got Cuban’s funding in October, the Hollywood company built up its team, adding developers and designers to do everything in-house, from art to animation to design. It now has eight employees.