Updated, 5:38 p.m. | LOS ANGELES — What's old is new: 20th Century Fox said on Wednesday that it would use a modern twist on one of Hollywood's hoariest marketing tactics — the sneak preview — to help sell the forthcoming comedic drama "We Bought a Zoo."

Fox has decided to hold "sneaks," industry parlance for an advance paid screening before formal release, on Nov. 26, a full month before the film arrives broadly in theaters, a signal of the studio's confidence in the movie's quality. Sneak peeks are normally done only a week in advance. Fox will partner with a social-video service called Tout – think Twitter only with 15-second videos – and Facebook. (Attendees will be asked to make Tout videos as they exit theaters, for instance, and be given 20 seconds as part of the tie in.)

It's the latest example of Hollywood trying to redesign its marketing playbook to capitalize on social media. If early reaction to "We Bought a Zoo" is as positive as Fox hopes, the studio will have created an online brush fire on behalf of the film. Other studios have recently tried versions of this to successful ends; Paramount, for instance, did a small sneak peek of "Super 8" over the summer (325 locations) in partnership with Twitter.

Fox hopes to book about 800 theaters across the country for the advance screenings and is working on more. "We Bought a Zoo," an inspiring tale about a family persevering, stars Matt Damon and Scarlett Johansson. The film was directed by Cameron Crowe, an Oscar winner for "Almost Famous" and a nominee for "Jerry Maguire." Oren Aviv, the studio's president and chief marketing officer, said strong feedback from test audiences led to the decision to do the early sneaks.

"We're lucky enough to have a picture to which audiences of all kinds and all ages respond," Mr. Aviv said.

Studios have been using sneak peeks since the 1930s (at least), but in recent years have typically resorted to them only in desperation. They are successful when early audiences respond favorably and tell their friends to go on opening weekend. But the opposite can easily happen. Paid advance screenings also siphon money away from opening weekend results, when box office bragging rights are measured.

These screenings, fairly or not, have also come to be seen as blood in the proverbial water — somebody is worried enough about turning out an audience that sneak peeks are on the table.

Fox does have a clear dilemma with "We Bought a Zoo." It's a quirky picture that could be read as a serious Oscar bet by audiences and thus not seen as the broad feel-good movie Fox is counting on. The movie, which opens on Dec. 23, will also be surrounded by lumbering colossuses like "The Adventures of Tintin," "The Girl With the Dragon Tattoo," "Mission: Impossible – Ghost Protocol" and "War Horse."

In other words, for "We Bought a Zoo" to have any shot at turning into the kind of "Marley & Me"-sized hit Fox is gunning for, the studio needs all the help it can get.