Watchtower followers don't understand that their corporation is mainly interested in protecting and increasing its financial (not spiritual) assets. They have just enough religion to maintain a veneer of "righteousness". A lot of money moves around into the Watchtower Society and into investments and real estate.
I've noticed that the Watchtower has since 2001 been very protective of its financial figures. To my knowledge, no facts like this $951 million in annual revenue has been leaked since 2001. I suspect two things: (1) They've gotten wiser about letting out any such truthful information that could potentially be used by their adversaries, and (2) they are still making a lot of revenue which they don't want their people or potential litigants (such as those who bring child-abuse cases) to know about.