insidetheKH: "...we should never extrapolate our own experience in a local kingdom hall to the rest of the world."
My understanding is that most of that growth is from 2nd and 3rd world nations with negative growth in the US and I believe Europe. I don't have the Yearbooks but I think that each nation has its different statistics. Comparing the US to Mexico might be interesting.
My belief, even when I was still in, was that "informal witnessing" to acquaintances and "worldly" friends was a better way of attracting people. It worked for me, having helped to convert two Pentecostals at High School. Never had any success at door to door though.