What exactly does how do you do mean? I'm ashamed to admit I say it and I don't quite know what it means. I'm also very curious to know, and I suppose this is a question of opinion, when did folks stop saying it? When did "how do you do" meet it's demise within society? I suppose whenever it was it must have had a precipitious decline of usage on account of I personally don't know anyone, besides myself, who says it today; however, I know there must be folks who still say it.