Why? Two Reasons :

• Cameron Works best With Traditional, even “Clichéd” Stories- Aliens, Terminator ( Cameron had to give Ellison Credit for Demon with a glass hand) and Terminator 2: Judgment Day, Piranha II, That Little A Night to Remember remake called Titanic. All were extremely successful even though they weren’t all that original. Cameron understands the “willing suspension of disbelief”. The large canvasses he unfolds his spectacles on require that the audience can follow the story. So, no. I’m not worried that Avatar’s concept can be summed up as ” Dances with Wolves” in Space. And I’m sure he’ll dumb-down the whole transference technobabble to a level even today’s post literate movie goers will think is cool. AVATAR will be accessible.
• 3D is no longer a gimmick- Until now there have been two kinds of 3d movies, those like Journey to the center of the Earth and The Final Destination who have no reason to exist except for the 3D gimmick to get butts in the seat, and those like Coraline and  Disney/ Pixar’s Up who would have been entertaining and successful anyway, but the 3D effect was an added bonus to get butts in theater seats. But Avatar promises that the 3D will be integral to the sweeping story Cameron wants to tell. In other words, to see the movie Cameron wants you to see, you have to go to the theater.  This isn’t the first time he’s done this. The Fall of the Abyss into darkness was always much more effective in the darkness of the theater than in the home. And I remember an article I read about how Cameron used to compose for the 4:3 aspect ratio of Television within the widescreen shot for the theater. Cameron understands that the movie experience will always be different than the home viewing experience, and is setting us up to need to go see Avatar in the theater.

The Avatar day screenings and ho-hum trailer are all part of what promises to be a new type of marketing campaign for an old type of film- a state-of-the-art spectacle that was designed from the ground up to be seen in only one place on Earth- The Cinema.  I have no doubt that when this films opens, audiences will have gotten the message and will lining up around the block to experience it.