It's not unusual to buy movie passes in advance, but for a movie that's still six months away?

That's one way to drive expectations up for the next Batman movie, "The Dark Knight Rises." While it's not the norm to have tickets go on sale so early, the idea to make IMAX tickets available in some cities came from an unlikely source: "Mission: Impossible: Ghost Protocol."

So thanks, Tom Cruise.

AMC Theatres was among the outlets that had shown a six-minute IMAX teaser prologue for "Dark Knight Rises" last month. As a way to capitalize on the buzz already being created for the film, those theater managers decided to make midnight opening tickets available to those who showed up for films in Los Angeles, New York and San Francisco, according to The Hollywood Reporter.

The results? Sold out.

That got the attention of online ticket seller Fandango which also started to offer midnight showing tickets for other theaters.

It looks like Warner Bros. is starting to gather money for the film long before it premieres, which can only add to the excitement behind what is being called the final film in director Christopher Nolan's Caped Crusader trilogy.

Could far-in-advance ticket sales be the new trend for theaters, which in the last couple of decades moved toward larger theaters, midnight showings, IMAX and a push for 3-D? How early should tickets be sold? Could we begin to see some theater chains convincing moviegoers to lock in tickets at 2012 prices for films coming out in 2014?

That's hard to tell. "Dark Knight Rises" is a unique case, especially since it's the third part of a trilogy that has already grossed $1.37 billion worldwide between 2005's "Batman Begins" and 2008's "The Dark Knight." Most of that money came from the second film, which alone grossed a little over $1 billion worldwide for Warner Bros.

However, other films have had success in advanced ticket sales, and have not been box office smashes. "Sex and the City 2," for example, had tickets go on sale more than a month before the premiere. Yet, that film finished short of its budget, hauling in $95 million in North America.

It could be a vehicle to lock in ticket buyers before reviews and other chatter start coming out for a film, the kind of chatter that could sink a film if it's not quality. It can be used to build early buzz for a film as well, if the practice becomes more mainstream.

"The Dark Knight Rises" starts Christian Bale, Tom Hardy and Anne Hathaway. It opens July 20.