Recently I read of Russells many failed armagedon prophesies, about every 4-8 years, from 1874 through to 1915 when he gave up. What is interesting is to also examine what was happening to the membership of the Bible Students organisation, as the JW's were called. In the build-up to the prophesised date the numbers would often surge dramatically (e.g. 100% increase) as people joined up out of fear of destruction. When the date failed many would leave (e.g. 20-30%) but there was always a net gain. Often it was said that the remainder who did not leave felt a strengthened bond to the group, possibly caused by some sort of shared trauma.
This is possibly the secret of the JW's success so far and I query some of the theories put to this forum that recent failed prophesy will ultimately or permanently damage the JW's. Perhaps their latest strategy of not prophesising an exact date may be even more detrimental to their existence in the long run, as the fear of imenent destruction is diminished. There are however other forces at work. The internet is one of them.