I like to think that I got an iPhone after carefully considering all the alternatives and making an informed technical analysis because I am a unique individual and I would never follow the herd or copy other peoples' actions. (At least that's what I tell myself.)
YOu could try to claim 400M. But each quarter, half the sales are upgrades. So maybe, what, 100M? Which is 1/4 of America. But all the sales aren't America.
Maybe 25% market penetration? Not small potatoes, but still, Most people haven't bought one.