'Most' of us were not born 'in any given month'. That doesn't mean we weren't born 'at all'. Inaccurate headline.
Very nice and succinct exposing of misuse of statistics. Thanks.
The percentage of users buying apps in a given month does relate to the overall number of app purchases. Also, we're only born once, but we can buy apps any time we want.
But 'at all' isn't the same as this or that month.