The way I see it is: the WT religion it is progressively becoming a religion of the old and marginalized. The WT is doing their best to dumb down the flock, the Internet is demonized, higher education is off limits, seeking a well paying job in the place of greater service to the organization heavily frowned upon.
It just don't spell a very successful or desirable religion over the averages of time with regard to wealth and prosperity it don't seem like a formula for success but rather a house of cards.
If there were some way to graph it,, say with the increase in population awareness of scientific developments and religions influence over the masses I'm sure that we would see an ever increasing down ward curve coinciding with with scientific information gathering with perhaps a few decade lag behind in the religious influence graph line.
As the curve of scientific advancement progresses upward and knowledge of science permeates the masses the effectiveness of gaining new recruits diminishes and only the already indoctrinated with religion form the vastly big majority in the congregations so much so that potential new recruits are scared away by the lack of intelligence that is not that obvious to the brain dead masses inside the congregation so that the potential new recruit sees the stupidity before the indoctrination process has had time to settle in in other words he sees in a relativily short time that the people are all nuts so he gets the hell out of there before his brain gets rigamortis..
The fact that the Wt has the most growth in countries that are underdeveloped and lacking education and scientific advancement does not bode well for the WT organization finances and future growth. Since the WT is a publishing company the Internet paperless information has severely cut down the profits newspapers and the publication of books and so forth this has also had it's bad effect of the income from such paper selling door to door work of JWs already resulting in lay off for many in Bethels throughout the world.
Where ever the Internet gains a foothold spells lower numbers in growth through information availability to the masses that seems to spell the eventual doom for the Wt paper publishing company(Save the trees). It may be true that the WT may be claiming to their member continued increase I find such increases rather hard to beleive and can easily be accounted for by the fact that the WT is very dishonest and has juggled the fact repeatedly in their attempt to mislead their followers.