It's fucking useless.
Well, yes. It's mostly because they don't understand the underlying problem with their dollars and euros as they are. But mostly because they don't care for anything more than a soundbite or an argument. A good way to start weeding out the receptive is by telling them to watch the Money As Debt videos by Paul Grignon.
http://www.moneyasdebt.net/
http://video.google.com/videoplay?docid=-2550156453790090544
It's unlikely that any but the smallest minority have the genuine interest level to perform such a minimal task as staring at a screen and listening for forty-seven minutes. (This is despite all the episodes of Jersey Shore they have no doubt watched.)
Survivors of this initial weeding may then be of a caliber to understand the arguments for Bitcoin.