WORD OF MOUTH - Vampire film is sure to draw blood

Every weekend, the studios turn to three research firms to help predict upcoming box-office numbers. The companies -- IAG Research, OTX and the National Research Group -- conduct different surveys, but their numbers all try to answer the same question: Are moviegoers interested in a new release?

The data is called tracking, and throughout the week (but especially on Thursday and Friday), marketing and distribution executives sift through the numbers as closely as a desperate 49er panning for gold.

There are always surprises, but a careful reading of the data would have shown that "Tyler Perry's Why Did I Get Married?" would open more strongly than many people assumed. So what do the numbers suggest for this coming weekend?

Four new films will open in wide release Friday: Sony's vampire film "30 Days of Night," Miramax's crime thriller "Gone Baby Gone," Fox's sports movie spoof "The Comebacks" and New Line's torture drama "Rendition."

The consensus is that "30 Days" will win the weekend, and while the predicted gross is estimated as high as $15 million, the film might do even better. Some people associated with the film are hoping privately it could gross more than $20 million, but $17 million seems the highest reasonable prediction. Sony has an excellent track record with genre films, holding six of the best 20 openings, including the No. 1 all-time winner, 2004's "The Grudge" with $39.1 million.

Second place will probably fall to "Why Did I Get Married?," with "The Game Plan" third and "The Comebacks" in fourth.

The bad news for the R-rated "30 Days of Night" is that it has but one week to make a real killing. On Oct. 26, Lionsgate will release "Saw IV," which will cannibalize the horror audience.

Even though "Saw IV" opens a week later, its tracking numbers are already ahead of "30 Days of Night" now, with stronger definite interest among men and women aged 21 to 30, suggesting it will open better than "30 Days of Night." (A year ago, "Saw III" debuted with $33.6 million in ticket sales.) "Saw IV" faces only one new movie in wide release, the family-friendly Steve Carell romantic comedy "Dan in Real Life."