Meet Magic Johnson, the media mogul

FORTUNE — Earvin “Magic” Johnson became an icon for his success on the basketball court. After his retirement, he became almost as well known as an entrepreneur, philanthropist, and HIV activist. Now, with major investments in radio, magazines, and a new television network, another Magic is emerging still, the media mogul.

Ask the affable Johnson if he’s reached that status quite yet, and he’ll simply laugh. But his ambition is serious. He is betting that recent moves could help him join the ranks of Oprah Winfrey and Robert Johnson, the BET founder who became America’s first African-American billionaire. If that seems unlikely, consider Johnson’s considerable wealth — estimated at around $500 million — and his portfolio and track record.

Through his company Magic Johnson Enterprises, Johnson has his hand in a bit of everything, from movie theaters to fitness centers and restaurants. He’s a serious player in real estate and worked with Howard Schultz to bring dozens of Starbucks (SBUX) franchises to predominantly African-American neighborhoods. He doubles as a tech venture capitalist through his position with Detroit Venture Partners. The firm, which holds 10 investments, focuses on re-building the Detroit area through entrepreneurship and technology — a goal that hits close to home for Johnson, a Lansing, Michigan native who won a national championship at local Michigan State.

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While the franchise model has proven successful for Johnson, long-time adviser and Magic Johnson Enterprises President Eric Holoman says the company has shifted to projects with greater social impact – and return on investment. Last year, Johnson sold his 50% stake in 105 Starbucks back to the company for an estimated $75 million and his 4.5% share of the Los Angeles Lakers to billionaire Dr. Patrick Soon-Shiong for an estimated $25-30 million. The Los Angeles Times reported the combined value at over $100 million.

But it’s in media that he’s growing his portfolio the most. His roster now includes the magazines Vibe, Uptown, and Blackbook; the library and brand rights to the iconic TV program Soul Train; seventeen radio stations; and now the basic cable network Aspire. The latter will be launched in a few weeks by Comcast (CMCSA) as part of that company’s mandated commitment to increasing the diversity of its offerings as an agreement with the FCC and Department of Justice following its acquisition of NBCUniversal. Aspire will be one of two networks offering content for the African-American community; Sean “P. Diddy” Combs heads up the other.

Johnson will be CEO of Aspire network. Holoman says that Johnson’s role will be “bigger picture, more directional and oversight.” Meanwhile, Holoman will be handling the “operating side.” Comcast doesn’t own any stake, but signed a distribution agreement after selecting the new network about five weeks ago.

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The larger goal, Johnson says, is to create a “one-stop shop for those who speak to minorities,” ensuring a voice for African-American creative talent across all media platforms. It’s access to such talent, and properties such as “Soul Train,” that reassured Comcast that Aspire would have plenty of material for its future programming, says Jen Gaiski, a member of Comcast’s content acquisition team who worked on the deal. With a strong team of co-investors through InterMedia, Gaiski adds, Aspire will be able to hit its stride faster.

Johnson’s first brush with media came in 1981 when he acquired a small radio station near Denver, Colorado. Johnson switched the station from AM to FM and later recouped the purchase price just by selling the surrounding land.

As his career with the Lakers exploded in the 1980s, so did Johnson’s business ambitions. Johnson says he wanted to be respected for his track record in business as much as his playing. “The basketball got in the way of his business career,” says Holoman, whom Johnson befriended during that period. Johnson made it a habit to associate with the executives who frequented his games. Many of his business contacts, such as CAA founder Michael Ovitz and Mandalay Entertainment CEO Peter Guber, have come straight from those basketball days.

That’s where many celebrities and former professional athletes have failed, says Alby Salaman, chair of Holland and Knight’s private wealth services group and lawyer to several NBA and NFL players. “Players are usually very loyal to their old friends, relatives, and teammates. And that means sometimes they don’t investigate their advisors enough and end up making poor business decisions,” Salaman says.

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Money, fame and lack of business skills have been the Achilles heel of many athletes’ business ventures. Retired NFL and CFL wide receiver Raghib “Rocket” Ismail squandered his fortune through a failed restaurant chain and bad – and bizarre — investments in experimental cosmetic procedures and three shops dedicated to selling framed calligraphy. Current NBA star Dwyane Wade faced a $25 million lawsuit for his failed restaurant deal with former best friend Marcus Andrews and another ex-partner.

In discerning the good advisers from the bad, Johnson didn’t fall for the razzle-dazzle that can lead to such disappointments, says Steven Rogers, a professor at Northwestern’s Kellogg School of Management who teaches business seminars for professional athletes. In fact, Johnson notes, he’s advised younger stars on their ventures, from Derek Jeter and Alex Rodriguez to Wade (not in time, apparently) and Shaq. As Johnson puts it, a leader has to know when to give up the ball. “You can’t bring the ego you had on the court to the boardroom or to your mentors,” he says.

Johnson’s ability to listen has paid off in the past. In the mid-90s, he partnered with Peter Guber, then-chief executive of Sony Pictures Entertainment (SNE), in a national chain of inner-city movie theaters. “He has a good BS meter. He knows the difference between words and deeds,” Guber says.

But that’s not to say that Johnson keeps a low profile in his meetings. Johnson’s business associates say they’re impressed his deal-making talents. “You’ve got to get a track record, and you’ve got to get respect,” Johnson says. “Now people don’t take the call because I’m Magic Johnson. They take the call because they want to do business with me; then I’m Magic Johnson.”