Exactly. If it's a mystery/thriller type of thing where the "revelation" at the end, is quite important and "changes" what I saw before... THen I guess a spoiler has a bit more importance.

But yes, generally speaking, if a movie can be spoiled by a spoiler... then it's not too good, to begin with. And Titanic is a good example indeed. It's way more than that. I mean... I see many movies more than once.

(Having said that trailers this day, tell us way more than they should. And personally, I love when I have the privilege of starting a movie knowing zero % about it. )