Slimboyfat...it is interesting you mention that "At the same time I think it’s only fair to acknowledge that JWs have done a much better job at retaining members than most other religious groups."
I remember that the Pew Research Center did a survey on youth retention in religions, and JW's were near the bottom of the pile at about 35% of youth raised in the religion staying on as adults. That does not portend well for the future numbers given the small number of outside converts being added.