What's the formula of a blockbuster?
In the case of both The Avengers and Avatar, you may enter the movie theater identifying with the powerless, weak, fearful, overwhelmed by external forces characters as portrayed by the "normal identity" humans or in the case of Avatar, handicapped identity of the protagonist. Such identities are flawed, and if not powerless, are at least fairly vulnerable traits that make it easy to identify and begin to vicariously live through if you are feeling less than superhuman these days. Then as the movie progresses (and it is also important to have a decent and not too cheesy story), such imperfect characters as those on the screen and in the audience become transformed into superheroes that can take on and defeat any adversity or even evil in their path. And by the end of the movie you get to personally experience being heroic, in command, in charge and control of all your domain.
It's also no wonder that many people go out for food or a snack after the movie, because as the vicarious adventure drops you back in a life that you are anything but powerful in, it may make you hungry for something to keep the high going.
Years ago, I did a workshop at a PromaxBDA convention that was high tech except for my standing-room-only, no-tech presentation to more than 250 attendees on "Creating Gotta See It!" PromaxBDA in the international association for entertainment professionals, who are responsible for the trailers, ads, opening TV and movie sequences (all designed to compel you to want to see more or what I referred to as "Gotta' See It!" This is the same experience behind, "Gotta Have It!" "Gotta Buy It!" "Gotta Tell Others About It." Contrast that with the opposite reactions, such as, "Never mind," "Nah, don't think so," "Pass" or "Yuck!").
The single hand-out from that presentation is below. In essence, what it means is that every customer who has the internal experience on the left wants a product or service to transport them to the experience on the right. In the example of a promo or trailer or title sequence, all of these should offer a viewer the promise of being transported from an experience on the left to the one on the right, if they see the TV show or movie.