CLEARFIELD -- The stacks of comic books End Zone Hobby Center gave away to customers on Saturday were gone within minutes.
A long line of comic book lovers had come out to enjoy Free Comic Book Day, an annual event celebrated by comic book stores across the nation.
It was purely coincidental that the opening of "Iron Man 3" -- also a hit comic book series -- debuted at the box office Friday.
The annual event has grown in stature from a few stores to some 2,000 worldwide. Retailers say the turnout and scope of the event, which began in 2002, is giving them and the industry a chance to tout their success by giving away 4.6 million comic books featuring everything from Superman to "The Walking Dead" to Gilbert Hernandez's "Marble Season."
The event was also a chance to extol not just comics as an art form, but as a nexus of pop culture, too, said Joe Field, who organized the first Free Comic Book Day in 2002 and has been its chief architect and No. 1 proponent ever since.
"That really is the crux of Free Comic Book Day, inviting people into these shops that are really social hubs for people who like anything that's going on in popular culture," he said.
"Comics are definitely a growing thing again, especially with all of the top selling movies that are all comic related," said John Irsik, owner of End Zone, referring to Batman, Spider-Man, The Green Lantern and Avengers, just to name a few. "I haven't met anyone who hasn't dreamed of being a superhero."
John Jackson Miller, who tracks industry sales figures and estimates through his www.comichron.com website, said that sales of single-issue comic books were up nearly $60 million to $474.6 million in 2012, compared with $414 million in 2011 and $310.6 million in 2003.
Miller said that digital sales of comics were an estimated $75 million in 2012 compared with about $25 million the year before.
"It's definitely tripled," he said of the gain. "The growth in digital sales has been substantial and the heartening thing to everyone in the business is that it happened alongside gains in print sales. There is no evidence whatsoever that the digital availability of comics -- released the same day as the print comics -- is pirating sales from the other."
Those picking up comic books at the Clearfield store came from diverse backgrounds. Some families were there to introduce their kids to comic books, others wanted to add to their comic book collections, while others were coming back to their love of comic books.
Zach Berrett, 21, of Ogden, remembers how much he enjoyed comic books as a young kid, but lost interest in them when he hit his teen years. Now that he is attending college, he has rekindled his comic book interest.
"It started piquing my interest again because of the whole aesthetic of the comic book with good artwork and stories," Berrett said.
Jerry Ryerse, of Clearfield, was at the event with his wife and three young kids, in hopes of getting them hooked on comic books.
"I was really into them when I was younger, so I think my kids will like them too," Ryerse said. "The fantasy world makes everything really cool."
Lucky Funderburg, 37, of Roy, said that the average comic book collector has around 10,000 comics. His collection is slightly smaller, ranging in the couple of thousands. He doesn't plan on reaching 10,000 because he only has so much space for his collection.
"If you get too many, then it can be a fire hazard," Funderburg said.
Angelina Starks of Syracuse got into comic books about 10 years ago when she began watching the TV series "Buffy, the Vampire Slayer" and "Angel."
"I found out those TV series had additional comic book stories, so it's been nice to get more into the characters you don't get to see on the show," Starks said.
The two television series have ended, but the comics keep them alive.
"I like being able to keep with something I enjoyed with additional spin-offs and more characters," she said.
Now Starks is introducing her 10-year-old son to the comic book world, especially because he is a big fan of the cartoon, "Avatar: The Last Air Bender."
"I like them because I've seen the cartoons, and the comic books have extra stories," Hunter Starks said.
For Jennifer Nicholson, of Clearfield, she has enjoyed the fact that her 7-year-old likes comics because it is helping him learn to read.
"As an emergent reader, it helps that he can see the picture with each sentence and he can see what the story is about, so it makes him want to read because he wants to know what is going to happen next," Nicholson said.
The Associated Press contributed to this story.