You may find this professional paper done by RODNEY STARK & LAURENCE R.IANNACCONE on Why the Jehovah's Witnesses Grow so Rapidly:A Theoretical Application that appeared in the Journal of Contemporary Religionto well be worth your time to read through carefully.
The Abstract:
This paper applies a general theory of why religious movements succeed or fail to explain why the Jehovah's Witnesses are the most rapidly growing religious movement in the western world. In addition to qualitative assessments of Witness doctrines, organisational structures, internal networks, and socialisation, we utilise quantitative data from a variety of sources to assess such things as the impact of failed prophesies, how "strictness" eliminates free-riders and strengthens congregations, the demographic make-up of the Witness "labor force", and the effects of continuity with local religious cultures on success.There is so much good information in this study, that I would have to nearly retype major portions of the entire paper. I don't think there should be any doubt that the WTS doesn't like this study.
Kind Regards,
Skipper