redvip there was an internal letter within a year of dropping charges in 1990 that stated income from literature was down. Every downscale in literature since then indicates the trend continued.
Don't forget that the bulk of Watchtower profit came from selling special and luxury items to JWs: insight books, deluxe Bibles, tapes, videos, yearbooks, Kingdom Interlinear, concordance, calendars, daily text, bound volumes, Bible stories book, individual magazine subscriptions...
I think we tend to forget just how huge Watchtower publishing used to be, and just how many items they sold to JWs, before you even begin to factor sales to the public.
The profit on each item may not have been massive, but they certainly weren’t selling at a loss, and with a captive market of millions it's easy to see how Watchtower we’re rolling in the money until the 1990s when the cutbacks began.
Any income prompted by donations for the dwindling literature today is negligible by comparison.