That’s the essential message here at the Cannes Lions advertising festival.

One guy who’s quite eager to see this trend advance is DreamWorks Animation CEO Jeffrey Katzenberg. On stage today with WPP chief Martin Sorrell and News Corp.’s James Murdoch, Katzenberg predicted how consumers will choose movies in the near future:

“Somebody is going to create a website. You’ll subscribe, go on it, and answer 10 questions about movies,” Katzenberg said.

Matching you with people who have the same likes as you, the site will help you choose the movie ideal for you.

With the mining of consumers’ movie preferences and actual choices, “You will know with a high degree of predictability whether you want to go to that movie,” Katzenberg explained.

Of course, Facebook, among other social sites, already helps users curate entertainment based on friends’ and other preferences. And one man who has tried to marry social networking and movie-selling, Netflix founder and CEO Reed Hastings, is joining Facebook’s board of directors, raising the game for both those companies.

Katzenberg, meanwhile, sees opportunity for some other innovator to steer movie choices — and implications for Hollywood as this evolves: “The movies have to be good,” he said. In Hollywood right now, he added, “there’s too much marketability vs. playability.” More social selection of movies “will yank (the power) back to playabilty.”

Murdoch, who is deputy chief operating officer at his father Rupert’s News Corp, agreed that demand for quality entertainment is only going to rise with social marketing. “There’s going to be nowhere to hide,” he noted.

Social networks, Murdoch added, will help consumers who feel lost amidst too many media choices. “It’s very hard to find things,” he said. “To use the social tools to discover content will be necessary.”