A look at Filmack Studios, which has produced classic movie trailers like "Let's All Go to the Lobby". The company, which opened in 1919, is now operated out of the Glenview, Ill. home of owner Robbie Mack. (John Owens/Chicago Tribune)

It's one of the most iconic movies in American cinema history, despite its running time of less than one minute.

In the film, four animated concession items — a candy bar, some popcorn, a box of candy and a soft drink — march up a movie theater aisle, singing a timeless tune, designed to get patrons to empty their pockets at the refreshment counter: "Let's all go to the lobby. Let's all go to the lobby, to get ourselves a treat!"

The film, not surprisingly titled "Let's All Go to the Lobby," is a movie trailer produced in the mid-1950s by Chicago-based Filmack Studios. And despite its age, it's still shown today in hundreds of theaters throughout the world, in addition to being parodied by everyone from David Letterman to "The Simpsons" to a host of commercials over the years.

The Library of Congress also selected it for preservation in the U.S. National Film Registry in 2000 for its historical significance.

"It's a cultural touchstone, the one film that was just pervasive in the theaters, especially in the 1950s and 1960s," said Daniel Eagan, the author of "America's Film Legacy," a comprehensive guide to all the films picked as National Film Registry titles. "It's probably been seen by more people than any other trailer ever produced. "

"It definitely has a cult aura," adds present-day Filmack owner Robbie Mack. "We're very proud of it and amazed that it's stood the test of time."

What's even more amazing is that Filmack itself has stood the test of time. The company, which produces non-coming attraction trailers for theaters and drive-ins, known in the movie industry as "snipes," has been around since 1919, when former newspaper journalist Irving Mack launched it in the South Loop. Since then, the company has produced thousands of "branding snipes" or "policy snipes," urging theatergoers to visit the concession stand, welcoming them to the theater, and telling them to not smoke, turn their cellphones off and keep quiet while the movie is running.

"Snipes have been around almost as long as the movies have," Eagan said. "Even early filmmakers like D.W. Griffith made snipes, urging customers to take off their hats in theaters. But no one has made them longer than Filmack."

Now in its 94th year, Filmack is the oldest movie trailer producer and distributor in the world. And what's even more impressive, it has been run by the Mack family throughout its entire history, making Filmack most probably the oldest company in the movie industry that has been run by one family.

"We've survived because I always try to follow the advice of my father and grandfather," said Robbie Mack, who followed grandfather Irving and father Joseph as the owner of the family business. "Their advice was always serve your customer."

Mack said that his company still sells a stock of about 200 trailers to "thousands" of theaters throughout the world, including chains such as AMC, Regal, Cinemark, Carmike, Century and Pacific. The company also does business with dozens of independent theaters, and especially drive-ins, which are a major consumer of Filmack's product. Trailers are sold outright to theaters for anywhere from $100 to $900 per trailer, depending on the how long the snipe is, Mack said.

But times are changing for Filmack.

Until 2006, the company distributed its product exclusively on 35 mm film. But the recent theatrical conversion to digital cinema projection has forced Filmack to face an uncertain future.

Industry experts say that 90 percent of the theaters in Europe and 70 percent of the theaters in the U.S. have converted from film to digital projection. And because of the cheaper costs involved with producing and distributing digital cinema, movie studios, large theater chains and independent companies have given Filmack a run for its money by supplying theaters with their own snipes, which are sometimes animated, other times live-action and often just simple slides.

For instance, Classic Cinemas, a chain that owns 13 theaters in Northern Illinois (including the Lake Theatre in Oak Park and the Tivoli in Downers Grove) used to buy snipes regularly from Filmack. But since the chain made the switch to digital in their theaters in 2012, Classic Cinemas' branding and policy snipes now come from a New York-based company called Screenvision, which offers custom-produced slides offering the same information.

"Filmack's been around forever and Robbie (Mack) is a great guy to deal with today," said Classic Cinemas owner Willis Johnson. "But we haven't bought anything from him since we made the switch to digital. It's just a whole lot different now than before, when you could splice a snipe to the front of a film. Digital changed everything."

Filmack has responded by digitizing its entire library, including "Let's All Go to the Lobby" and other classic snipes, to a digital projection format called Motion JPEG 2000.

But that brings about another conundrum. In the film projection days, exhibitors would buy a print of a Filmack snipe outright, and then run the film repeatedly until it was scratched and worn. When the cinema owners would need another copy of, say, "Lobby", they would then contact Filmack, which would sell the theater a replacement print. These days, however, once Filmack sells a theater a digital snipe, that file can screen continuously for years without the need to reorder a new one.

As a result of all these issues, Filmack has had to downsize in the past year. For most of its history, Filmack was located at 1327 S. Wabash Ave. in the South Loop on what was historically “Film Row,” which stretched from Eighth Street to 15th Street on Wabash Avenue, and included the Midwest distribution offices of all the major movie companies. In the “Film Row” days, Filmack had as many as 30 employees and branches in New York and Los Angeles.

Filmack relocated to the River North neighborhood in 2006, but the company still had up to 15 employees in recent years.