"We're going to show you five minutes of the movie every year for 20 years," comedian Patton Oswalt joked as he introduced the most recent trailer for Disney's upcoming release Tron: Legacy at last week's Comic-Con in San Diego. It was the film's third consecutive promotional appearance at the annual convention, an unprecedented amount of shilling for one movie.

Tron's extended marketing campaign (the film won't hit theaters until Dec. 17) mirrors—and hopes to be as successful as—Glee's promotional experiment last year. Fox began teasing Glee over a year before its official premiere, a strategy that led to the show becoming the year's highest-rated new comedy. The New York Times examines what all this means for the future of the Hollywood hard sell:

The selling and selling (and selling) of "Tron: Legacy" is the Hollywood marketing machine in its highest gear yet. Marketing campaigns for what the industry calls "tent-pole" movies -- big budget, big risk, big potential payoff -- have traditionally started about a year before their release in theaters. Increasingly, that is scarcely enough time.

With DVRs undermining the No. 1 tool for promoting movies -- television commercials -- studios are trying to create Internet brush fires on behalf of their coming releases. One variant is a controlled burn: carefully doling out bits of information over months and years.

Lead time also makes a big difference when it comes to breaking through the advertising clutter and competing entertainment options. In a post-"Avatar" world, the goal at the multiplex is to make movies feel like must-attend events; longer campaigns can help achieve that.

Read the full story at The New York Times.