The Dark Knight cover analysis

The Dark Knight is Promoted through both stars and genre:

• Christian Bale (Batman) sells the film with Michael Caine, Heath Ledger, Morgan Freeman, Gary Oldman, Aaron Eckhart and Maggie Gyllenhaal.
• Christian Bale stands alone on the cover yet he is stood strong indicating independence.  Both Christian Bale and his character (Batman) promote the film.
• The genre of action is promoted through the use of colour, setting and the characters shown. 

http://www.moviemarketingmadness.com/blog/2008/07/movie-marketing-madness-the-dark-knight/

The Dark Knight is also promoted through both stars and genre in its posters and trailers:

• Michael Caine promotes the film during its teaser trailer. The colours and shattering of the batman symbol during the clip indicates action. The other trailers show all of the main characters and stars throughout the clips.
• The posters tend to stick to the colours of blue, black, red and white; this combination works well with the genre of action.