Compete.com provides an interesting glimpse at the search traffic and trends surrounding the release of The Dark Knight as compared with recent releases Iron Man and Indiana Jones and the Kingdom of the Crystal Skull.
They found, among other things, that search traffic for Batman Begins after the release of The Dark Knight was greater than searches for all three previous Indiana Jones installments. This hints at an increased viewership for Batman Begins thanks to the record-breaking run of its sequel.
The article also examines the surrounding search terms (ie: trailer, sequel, etc.) for the three movies mentioned above, and interestingly The Dark Knight’s most popular searches didn’t include “game” or “video game” while both Iron Man and Crystal Skull did. This may calm recent claims that not creating a corresponding Dark Knight video game has hurt the movie and/or the video game industry in general.
You can read the full article, complete with charts, at Compete.com.
Release Date 11/14/2008 
