Research - The History of Film Trailer Timeline

Movie trailers have developed a life of their own over the last 50 plus years, and have evolved as much as the movies themselves have changed. Their style and pace have developed and changed many times, with each decade having its own recognizable form.

Many unique characteristics define horror trailers in particular from each decade, this is especially true in sci-fi and horror films.

The 1950s film previews:

• had longer trailers.
• told the whole story, or almost revealed the whole plot.
• flashed words on the screen, such as: "Terrifying! Close your eyes! Never before seen!"

The 1960's movie trailers:

• Still used bold flashing words.
• Tried to build on famous actors' names.
• Used narration to summarize the story.   
• Often showed the ending of the movie, in order to reveal an exciting effect.

The 1970's previews

• Were still too long, but tightened up a bit more.
• Revealed less of the story, but still showed many key or spoiler scenes.
• Enjoyed teasing us with mis-edited scenes, often out of order.

The 1980's movies had trailers that were tighter:

• More abruptly edited.
• Told very little about the movie.
• Often included scenes that were cut from the final edit of the film.
• No spoilers, and instead total mystery about the endings.
• Began to revel in catchy tag-lines.

The years 1991 to current have shown an evolution toward rock music backgrounds, and zoom editing styles. Not only are the endings a mystery, the whole plot is a secret. We may only get a series of random images thrown at us in an exciting style meant to entice us, all with a popular rock song in the backdrop.

The current trend features the use of

• Current rock or pop music, often from a new or popular artist.
• Shows less and less of the real story.
• Quicker editing and zoom effects.
• Often these trailers are more exciting than the actual movies. 
• Greater use of publicity stunts such as internet viral marketing or Facebook campaigns

Reference:   http://www.horrorfilmtrailers.com/extras/history-of-film-trailers.html