Sure, it's a shamelessly shrewd marketing ploy, the same kind Paramount rolled out so successfully four years ago in support of writer-director Oren Peli's original low-budget shocker about suburbanites terrorized by an invisible demon. But if you want Paranormal Activity 3to premiere in San Francisco on Oct. 18, three days before it opens in theaters everywhere, you must cast your cynicism aside and make your voices heard on Twitter.

In an unprecedented move, Paramount will debut the latest Activity prequel (directed by Catfish's Henry Joost and Ariel Schulman) early in 20 cities where the most fans "tweet to see it first." To vote, visit the movie's official site and select our fair city from a global map; the corresponding link will automatically create a tweet with a special set of hash tags to publish on Twitter. Each tweet counts as a single vote.

With almost 450 votes, San Francisco is currently languishing in 13th place worldwide, behind cities including Tel Aviv, Los Angeles, New York and leading vote-getter Houston. Full disclosure: I wasn't a fan of the original, though last year's follow-up improved slightly on Peli's hokey formula. Regardless, I am a fan of movies premiering in the Bay Area, whether Milk, Moneyball or even a superfluous scarefest like PA3. So get tweeting!