Also, in the USA most charities send out requests for donations at this time of the year.
Obviously, in virtually no sense of the word is Watchtower a "charity", but they are considered as such for tax purposes.
The Watchtower always makes a pitch for donations in November, just before the end of the year, trying to snare donations from the handful of wealthy JWs around who want to increase their charitable giving before the end of the year so as to get a tax break.
Most JWs of course live paycheck to paycheck and certainly don't itemize their deductions, but what few "big time" donors there are, are mostly living in the USA. So every year they send out the reminder "give us money so you can have a slightly smaller tax bill" directed primarily at that elite group.