Where as once posters serve as the face of the film, the primary form of advertising since once the only real way to see a trailer for an upcoming movie would be a the cinema previews screening or "TV spots" played at home, the fact that now the majority of the movie going population now has access to the internet in some form (or at least you do since your reading this) has altered the way in which upcoming films are advertised.
Today through the use of video sites such as YouTube anyone and everyone has access to previews of upcoming movies on demand, so the movie poster (once the main tool in the advertisement tool box) role is greatly diminished, we have even reached the point where upcoming trailers are advertised my trailers (The "Inception" of advertising)
I agree that you will probably be more compelled to go see a movie that you have an idea of what to expect and this is the trailers sole purpose but as a direct result the significance of posters in film advertising
resulting (In my opinion at least) in a decline of the quality of poster and ultimately "Box Art" a prime example of this is the movies 1975 movie "Jaws"
A brilliantly creative and simple poster that was successfully able to sell the idea of the film through a single image (Big Shark eats Ladies) that has since become an standout image and the first thing you think of when the movie "Jaws" is mentioned.
Or Drew Struzan's iconic series of posters made for the "Back To The Future" Trilogy
|Back to the Future (1985) by Artist Drew Struzan|
Or more to the point any of the posters produced by this fantastic artist, his work including (To name but a few)
|The Thing (1982) by Artist Drew Struzan|
|Star Wars: Episode I (1999) by Artist Drew Struzan|
|Blade Runner: The Final Cut (1982) by Artist Drew Struzan|
|Hellboy II: The Golden Army (2008) by Artist Drew Struzan|
|Goldeneye (1995) poster designed by Terry O'Neill, Keith Hamshere and George Whitear|
But as the age of online marketing moves forward and the demand for such advertising material becomes second to video marketing the effort spent on these images and as a result
|Gangster Squad (2013)|
And while not bad posters ( I rather like the B-Movie style approach to Gangster Squad) the sense of effort and artwork is lost and the dramatic flair is largely diminished.
Make no mistake there have still been many great posters released in recent years such the majority of the "Inception" advertisements, "X-Men: First Class" produced two great poster but eventually went for a lesser design and "Shutter Island" posters are other examples the jump to mind but poster design now seems more calculated and instead of giving the movie a face aims to enforce things that the trailer has already presented the viewer.
The art seems to have left the advertisement and I cant help but feel like we have lost something important.