Overwhelming 3-D Sales Help 'Gravity' Smash October Box-Office Records

The film exceeded all expectations, earning a huge $55.5 million.

That gives director Alfonso Cuaron's film the highest-grossing opening weekend for the month of October at the box office.

Previously, "Paranormal Activity 3" held the record, making $52.6 million back in 2011. The Paramount film was made on an estimated $5 million budget - far less than the $80-$100 million estimated cost of "Gravity."

While the film has been getting glowing reviews, that's not the only reason the space epic had such a large opening weekend.

Most people were shelling out the big bucks to see the film in 3D.

Take a look:

As many people were seeing the film in 2D as they were IMAX.

IMAX showings accounted for 20% of ticket sales ($11 million).

This break down shouldn't come as a surprise as the majority of screenings that were available for the film this weekend were 3D and 3D IMAX. You were hard pressed to find a 2D screening of the film.

For the weekend's entirety in NYC, we found two to four screenings of "Gravity" in theaters on any single day. Compare that to at least 10 screenings per day in Real D 3D and five in IMAX 3D.

The price for an IMAX 3D ticket in NYC ranges from $17.50 (kids and seniors) to $21.50. In New Jersey, that can be compared with $13.00 (morning screening) to $18.50.

The average price of a 2D ticket is $8.38.