Can superheroes and fanboys save the box office

Based on the 150,000 fans flocking to this year's Comic-Con, many dressed in elaborate movie-inspired costumes, you'd never guess that the summer box office is suffering.

Since that all-important season started in May, U.S. ticket sales are down 19 percent compared with last year, while the year-to-date box office is down about 6 percent. Hollywood needs a hero. And it might very well have some in the films coming up in the next month, including Marvel's "Guardians of the Galaxy."

An attendee dressed as Spider-Man arrives for Comic Con 2014 in San Diego.
Harriet Taylor | CNBC
An attendee dressed as Spider-Man arrives for Comic Con 2014 in San Diego.

What went wrong?

Hollywood had its share of solid hits—like Marvel's "Captain America," which grossed $258 million in the U.S. and $713 million worldwide, and Fox's "X-Men," which brought in $231 million in the U.S. But there simply wasn't a *mega* blockbuster on the scale of last year's "Iron Man 3," which brought in $174 million at U.S. theaters opening weekend alone, and went on to gross a total of $410 million in the U.S.

Part of the problem is growing competition: between the World Cup, and big event television like "Orange is the New Black" and "Game of Thrones," people simply have more entertainment options than ever.

But there have also been some issues of scheduling and timing—"Fast and Furious 7" was postponed from this July to next summer because of Paul Walker's tragic death. Rentrak's Paul Dergarabedian estimates it could have added $200 million to the U.S. box office.

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Can things turn around? Yes—slowly but yes.

Films are already starting to gain momentum—"Transformers: Age of Extinction" has grossed more than $230 million in the U.S. and "Dawn of Planet of the Apes" opened with over $73 million, and more than $155 million so far.

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And expectations are high for Marvel's "Guardians of the Galaxy," which opens a week from Friday. Of all the films coming out, the dozens of people we talked to at Comic-Con say that's the movie they're most excited to see. The film has a rare 100 percent critics rating on Rottentomatoes.com and a 99 percent "want to see" rating from nearly 10,000 users.

The quirky, comedic superhero film could draw wide audiences—male, female, young, and old—to create a huge hit. Though sources say early tracking projects an opening weekend U.S. box office around $60 million, others say it could be as high as $70 million, which would set a new record for August.

That's not all—there are other potentially big films including Paramount's "Teenage Mutant Ninja Turtles" coming out in August. And this weekend Universal's sci-fi film "Lucy" is expected to be huge. In fact, "Lucy," which has a budget sources say is around $40 million, could beat Paramount's "Hercules," whose budget, sources say, was as high as $160 million.

That speaks to the fact that the top-line box-office numbers can be deceiving. The total U.S. grosses are not as important as profitability, and there have been plenty of profitable hits, like Universal's low-budget horror flick, "The Purge: Anarchy."

And the declining U.S. box office doesn't speak to the massive success Hollywood films are having overseas, especially in fast-growing markets like China. The latest "Transformers" has set an all-time box-office record in China, grossing more in that country than in the U.S. in just its first 10 days in Chinese theaters.

2015 could be the biggest year ever

At the end of the day box-office performance comes down to the individual films—how good they are and how much of an "event" they create to get people to spend on a big night out. And next year could be the biggest on record and the first to cross the $5 billion revenue mark, said Dergarabedian, predicting we could see as much as a 20 percent increase over 2014.

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Why? "The Avengers: Age of Ultron," could top last year's massive "Iron Man 2." "Jurassic World" from Steven Spielberg's Amblin and Legendary, distributed by Universal, promises to be huge, as does "Ted 2" and for kids, a "Despicable Me" spinoff.

—By CNBC's Julia Boorstin