"For several months, sometimes a year-plus, the studios behind these projects titillate fans with provocative sneak peeks — casting announcements, photos, trailers, alternate reality games — until it’s finally time to deliver the full monty: the movie itself"...
And, for a detailed look at the transmedia marketing campaign for The Hunger Games, visit How ‘Hunger Games’ Built Up Must-See Fever ... you may want to skip straight to page two of the article :)