sir82, you're on the money with your observations. Yes, socio-economic pockets of JW growth occur even in countries where there is overall stagnation in numbers of JWs. Poorer parts of society and/or immigrant groups tend to show interest in the JWs' message - indeed, religiosity in general among these kinds of groups is higher.
In New Zealand, for example, it is not uncommon to see Pacific Island mega churches in poorer areas - the ones that flourish here are the Pentecostal brands such as Assemblies of God. There is also strong connections with the American so-called "Big Three": Mormons (LDS), 7th-Day Adventists and Jehovah's Witnesses. Yet, there is no disguising the overall trend away from "Christian" religiosity in developed countries. The exponential growth is among Moslem and Hindu immigrant groups.