Ya I like how a 19" crt is only 17" viewable. Kinda seems like false advertising huh?
Well at least with a CRT there is something which is the measured size, even though people are not expecting that. Go check out 2x4s at the local building supply store. I tused to be that was the size of the finished product, but now it is the size that they start with. It seems very much like false advertising and it is quite deceptive, plus is makes people not be able to determine the real size of things.
Such practices creates issues like this were a person gets a disk and then finds it is not as large as they were lead to believe. Trust is broken with all retailers.
In a similar vein, consider resumes and the acceptance of it not being accurate, which hurts those who are accurate.
If some manufacturers were to be accurate, it would hurt them since people would compare the claimed sizes.
If you really want fun numbers, check out sleeping bags!!!