Perhaps I misunderstand the tech aspect of spoilers, but I thought primarily the spoiler was to hide something for purposes of a joke, poll, etc. Also, since we do sometimes deal with war and combat topics, and somewhat graphic but otherwise permissible pics might be used, it seemed spoiler tags were a good way, with a written notice, to protect those forum users who didn't want to view images which might disturb them.
But I also thought spoilers were a way to save some bandwidth for the site, or make it easier for the user to load what would be a pic-heavy page unless spoilers were used. Do I misunderstand the tech aspect about this and it doesn't really save space or time to use spoilers?