Kinda of hard to find a comparable film. I chose Dark Knight b/c of the buzz (both fan and critics) and since it was not 3d.

I looked at approx. 40 theaters in the KC district (21 3d and 19 2d). Overall the score for 3d theaters (Avatar divided by Dark Knight) was 43%, while non-3d was 32%. So yes, you can say that being 3d was very important.

One town of 100,000 people was interesting to me as the 14-plex in town just added 7 Sony 4k projectors (they ran 3 rooms of 3d Avatar). Previously the other 8-plex in town had 1 digital/3d room. Before Avatar, the 8 plex had averaged 2.31 times more than the 14-plex. Last night that swiched to a ratio of .52. the 8-plex has a sister theater 30-ish miles away without any digital screens. Those two theaters normally gross pretty close to the same amount. The 3d plex has been outgrossing the 2d (on 3d movies) 2.87x. Last night was 2.57.

So maybe the pie is increasing? Which is critical for long-term digtial success.

Of course, very limited sample and too soo soon to glean much info.