Also, if it were just the same people buying year after year, then you would see same YOY sales. However, Apple has been growing sales continuously so you can't really make the argument that it's just the same people.
Anyone can guess. It takes no effort to throw out lots of predictions and have some of them be correct. You are not and wiser or better for having your guesses be right. Even a blind man can hit the bullseye.







