Mark Cuban says one of the best investments he’s ever made is something anyone can afford

Self-made billionaire Mark Cuban
Fort Worth Star-Telegram | Getty Images

Mark Cuban started with just $60 in his pocket before launching his first business, MicroSolutions, which he sold to CompuServe for $6 million. Five years later, the entrepreneur co-founded, which Yahoo bought for nearly $6 billion.

Today, Cuban owns the Dallas Mavericks, stars on ABC's "Shark Tank" and is worth more than $3 billion.

If you asked the businessman about one of the he's ever made along the way, his simple answer may surprise you: Books.

"I used to love to walk through bookstores," Cuban tells Vanity Fair. "If there was something that caught me eye and I thought it could give me one idea — to spend $30 to give one idea that could help propel me and make my businesses better, it was a bargain."

These Mark Cuban quotes reveal his exceptional work ethic
These Mark Cuban quotes reveal his exceptional work ethic

One book in particular "used to get me all fired up," he continues: "The Only Investment Guide You'll Ever Need," written by Andrew Tobias in 1978. Another particularly influential book helped him earn his first million, he says in an interview with Money: "Cashing in on the American Dream" by Paul Terhors.

Cuban's not the only billionaire who makes time for books. Take Bill Gates, who reads 50 books a year, or his friend Warren Buffett, who spends as much as 80 percent of his day reading.

Reading and thinking helps Buffett "make less impulse decisions than most people in business," he once said.

For Cuban, reading sparks inspiration, he tells Vanity Fair: "I'll read hours every day because all it takes is one little thing to propel you to the next level."

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Money classics, summed up in one sentence
Money classics, summed up in one sentence