Viral Marketing Campaign: The Dark Knight

http://www.youtube.com/watch?v=vuE_ibcOdkE
It won't let me embed!
But anyway, the summer blockbuster The Dark Knight was filmed in Chicago, Illinois, and during filming the cast and crew would host rallies like this one to spread the word about Harvey Dent, who is one of the main characters in The Dark Knight. Videos like this one got posted all over YouTube and sparked interest in the movie. People that were not familiar with the character Harvey Dent got curious and probably googled who Harvey Dent was, thus creating buzz about The Dark Knight.
Additionally, various posters and faux Gotham websites were created with the joker's disturbing graffiti all over them. Even Gotham newscasts were created to spark interest in The Dark Knight. The joker's graffiti drawings became a huge trend during Summer 2008 all over the internet, which in part led to the huge success of The Dark Knight.