Large Movies / Small Titles

Here’s something that’s always confused me. Whenever you see advertisements for the latest movies, they’re always displayed with wild colourful font, showing how exciting and grandiose the presentation's going to be!






































And when you actually go to the theater and the opening credits start, you're faced with a tiny ordinary font on a black background. With none of the imagination of the posters.






Why is this? Did the producers blow so much money on their movie that there was nothing left to spice up the credits a little? Would it hurt them to even use the same title in their advertising? This might be an exaggeration, but a cursory look at a movie title database shows that this kind of thing's been becoming more common.