>>87
Actually, the reason sage exists in 2ch boards is to keep threads FROM the top. Users in 2ch don't like their threads being on the front page because it attracts trolls and undesirables. If there is a semi-private discussion going on out of sight and you bump the thread, they usually get mad at you for bumping the thread to the front page.
I think this is a very bizarre behavior, in 4chan the opposite is true, everyone wants their thread to be on the front page and if you post without bumping (sage'ing) their thread, they take great offense to that.