Paddy, I think the difference was that in the early 70s, large numbers of people received knowledge, and while the vast majority did not stick around, there was still a core of people who got indoctrinated into believing they were on the path of God realization and that Maharaji was the messiah.

In the late 70s, and in the 80s, on the other hand, not very many people received knowledge, and, of course, the vast majority of them left as well, perhaps even a higher percentage (virtually all, from what I gather) than in the 70s.

One of the differences between those periods was at least in the early 70s the cult was honest about what it believed.  After about the late 70s, the cult became dishonest in its propagation, trying to hedge on the belief system lest people be scared off.  Hence, premies had to start lying about what they really believed, or at least not talk about what they really believed.  This made propagation dry up because premies basically haven't a clue what they are supposed to say.  They spout the (current) cult line, but that's it, and it feels dishonest and so most premies are reticent to do it.  Hence, the miserable results the cult has had in the past 30 years.