"Iron Man 3"

"Iron Man 3" ruled the summer box office. (Marvel)

Yes, audiences have yet to tire of most sequels and remakes. But if your movie resembles another one too closely, it can spell disaster. That may have been the problem with "White House Down," released in July, in which an aspiring Secret Service agent helps protect the president as 1600 Pennsylvania Avenue comes under terrorist attack.

Despite its star power — Channing Tatum and Jamie Foxx — the Sony movie couldn't top the more modestly budgeted "Olympus Has Fallen," which was released four months earlier by FilmDistrict and centers on a Secret Service agent who tries to stop a North Korean-led attack on the White House. "White House Down" grossed $25 million less domestically than "Olympus" — even though it cost $80 million more to produce.

"R.I.P.D." was another film rejected by audiences perhaps because it seemed redundant. The film about two cops who come back from the dead to fight crime on earth reminded many of the "Men in Black" franchise. Likewise, with its hulking robots, "Pacific Rim" was often compared to the "Transformers" series, and didn't do as well in the U.S. as Warner Bros. hoped.

Moral of the story? Hollywood needs to get more creative, or start putting more space between expensive films with similar themes.

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4. Exhibitors are becoming more flexible, and it's paying off

About 89% of the 40,045 screens in the U.S. are digital — up from 75% in August 2012, according to the National Assn. of Theatre Owners. Now, studios don't have to transport heavy physical reels, and theaters can be more nimble: When a movie sells out in one auditorium, an exhibitor can easily decide to put that film in a bigger space the next day or add show times at the touch of a button. Conversely, films that aren't working can be pulled.

Theater owners are maximizing grosses in other ways too. Instead of opening at 12:01 a.m. Friday — as was long the custom — many highly anticipated titles have been debuting between 7 p.m. and 10 p.m. on Thursdays. That's because exhibitors began to notice that filmgoers were more apt to show up at earlier hours, and they asked studios if they'd be amenable to Thursday night screenings — a mutually beneficial agreement.

5. 3-D is falling but it's not going away.

American moviegoers have been increasingly less inclined to shell out extra bucks to see a movie in 3-D, but this summer, their interest really dropped. When "Turbo" debuted in July, only 25% of the opening weekend crowd opted to see the movie in 3-D, an all-time low for the format. Other family films fared little better, as "Despicable Me 2" only did 27% of its Independence Day opening weekend business in the format.

While kids' films have always been less popular 3-D options, even movies that seemed more fitted to the medium faltered, like "World War Z" (34%) and "The Great Gatsby" (33%).

Still, don't expect to stop seeing 3-D movies in theaters any time soon. While it costs studios extra to produce movies in 3-D, there's minimal added cost to distribute 3-D movies. Technology now allows digital prints to be switched between 3-D and 2-D at the turn of a key, so cinema owners don't have to offer as many 3-D showings if audiences aren't expressing much interest.

While U.S. filmgoers may not be crazy for 3-D, studios aren't particularly worried because international audiences love it. With the exception of "Fast & Furious 6" — a franchise that has been set in countries like Japan, Brazil and Britain — all of the summer's biggest hits overseas have been 3-D movies.

The recent moviegoing boom in countries like Russia and China has coincided with Hollywood's embrace of 3-D, and many foreign audiences feel 3-D is essential to the experience. In China, where piracy is rampant, the 3-D option can entice someone to choose a theater over an Internet download or a street vendor's illegal DVD.