The billion-dollar old man: Batman turns 75

Batman

Bruce Wayne might be rich, but his alter ego Batman is super rich and still raking in billions.

The Caped Crusader is one of the most successful superhero franchises of all time. He's starred in more theatrical movies than any other character, sold more than 10 million comic books last year alone and earned $11 billion globally for licensed merchandise. Not bad for a guy at the ripe old age of 75. How does the Dark Knight keep rising to new heights?

DC Comics co-publishers Jim Lee and Dan DiDio believe modernizing the character has been key.

"The art form of comic books has always invited different generations of creators to do their version of Batman, to contemporize him," explained Lee, who has illustrated several Batman comics. "You've seen over the years his costume change, different Batmobiles introduced, different supporting casts and different villains. So in that way, he's always been kept up-to-date. Every generation has their own Batman that they can embrace."

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This is a big year for DC Comics, which is the second-largest comic publisher after Marvel , with a nearly 30 percent market share. In addition to celebrating Batman's 75th anniversary, the company has a total of five TV shows based on its characters coming out this fall. CW is premiering three shows: "Arrow," "The Flash" and "iZombie." NBC picked up "Constantine" based on the comic series "Hellblazer." Batman also returns to TV in Fox's "Gotham." He'll also star in Warner Brothers' new movie "Batman v Superman: Dawn of Justice" in 2016.

"It's great to have such a pantheon at DC," DiDio said. "We have Superman, Batman and Wonder Woman, and all three of these characters represent something so important to all of the fans here and throughout the world."

While comics are fun, they're serious business. Exposing superheroes through multiple media such as film, TV, online book stores and video games attracts new and bigger fan bases, which Lee said provides a boost to comic book sales across the industry. In 2013, digital and print sales of comics and graphic novels hit a record $870 million in North America.

What's surprising is that, while sales of digital copies have nearly quadrupled to $90 million last year, from $25 million in 2011, print sales have not eroded.

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"Comic books have never been healthier, with growth in the print side and also the digital side," Lee remarked. "What we've found with the digital channel is that we've put a comic book shop in everyone's pocket through the phones or their tablets. People are able to click links and find that we're still publishing comic books. It's a great way of bringing people to our business and making them fans of the books themselves."

-By CNBC's Marqui Mapp