One reason why screen writers do this is draw attention to the conversation when it is used. The audience straightens up in their seats when they hear those key words that are on the movie poster. They go "Ahhh so that's what it means," or "That's what they're talking about!"
Sometimes they use the title just to be witty about it and others times it is something that cannot be avoided. For instance, in "Back to the Future" Doc tells Marty that he will send him "Next Saturday night, we're sending you back to the future!" as he points straight toward the camera. Instances like this are ones the moviegoers cannot miss.
When John Hammond introduces Dr. Grant and Dr. Sattler to Jurassic Park it is inevitable the place's name will be mentioned eventually. "3:10 to Yuma" is another movie where it is unavoidable to mention the name of the train they are trying to get Ben Wade to.
|"Welcome to Jurassic Park!"|
The James Bond films are classics for mentioning the title in the films at some point or another. They vary from the names of the bad guy, such as "Dr. No" and "Goldfinger," to a phrase that Bond or another character will say like "The World Is Not Enough" and "For Your Eyes Only."
Others are mentioned at the very end such as "The Dark Knight" and "The Breakfast Club." These add power and meaning to the very last minutes of the movie.
Sometimes the title drop is used in the explanation of an idea. "The Prestige" and "Inception" are examples of these. The viewers are supposed to not know what either of these titles mean in connection with the movie. It becomes the characters responsibility to explain what the concept means in the dialogue.
|"Listen, there's something you should know about me...about inception. An idea is like a virus, resilient, highly contagious. The smallest seed of an idea can grow. It can grow to define or destroy you."|
Below is a mash-up of examples of movies using the title drop. Listen carefully and scroll farther below for the order of the movies. If you didn't catch the titles you might want to check your hearing or maybe your movie knowledge.
Order of the title drops
1. "Back to the Future"
2. "The Breakfast Club"
3. "The Prestige"
5. "3:10 to Yuma"
6. "The Dark Knight"
7. "Die Another Day"
8. "Full Metal Jacket"
9. "Jurassic Park"