An Index of traditional movie poster sites can be found in this site's movie memorabilia links section. Collecting movie posters is one of the most popular areas of collecting among movie memorabilia collectors.
Many people exclusively collect posters, and prefer to avoid all other movie collectibles even.
Posters have been printed to promote movies in theaters for nearly a hundred years. The fact that most posters are thrown out or destroyed with time, has made many once common posters now invaluable. A traditional movie poster's value is largely determined primarily by its condition relative to its scarcity. There does exist a rare breed of posters where condition is a secondary concern to actually finding the posters. Movie productions often make posters to represent fictitious movies, or events.