This may have been the coolest thing ever when I was growing up. I tried to explain the concept of having a machine that could make fizzy drinks to the teenagers that I teach - they just didn't really get it. "But you could have all different flavours!" I argued. "And it cost significantly less than buying bottles of the stuff!" They looked at me blankly. "You could also choose how concentrated you made each drink!"
In desperation, I showed them this advert. It didn't help.