YouTube star iJustine is taking us through the evolution of Comic-Con, now underway in San Diego.
iJustine has become a Comic-Con expert, having been coming to the popular event since 2009.
"It's just insane," she said. "It gets bigger and bigger every year."
What Comic-Con is today is a far cry from how it started four decades ago. In 1970, "it was a bunch of guys with comic books who were swapping them and trading stories," according to Entertainment Weekly's Matt Bean.
Somewhere along the line Hollywood saw the potential for using the event for movie and TV promotion, which drew major attention to the convention.
"It's become a platform to test out films that they want to see how the audience might react to," Bean explained.
While most Comic-Con goers make the trek to have a good time, there is a seedy underbelly to the convention. Watch the video to learn about Comic-Con's dark side.