I know that SBF is not an apologist for the JW's - merely reporting what he sees locally :-)
When I born captive in 1969 there was one baptism for every 2000 hours of preaching. In 2010 it hovers around 5000 hours.
More significant is the number of hours required for an additional publisher. Due to the large increase in Witnesses leaving the religion, the number of hours preaching required per additional publisher has doubled from 4,000 in the early 1990's to over 8,000 since 2000.
Those numbers reflect the fact the JW's are running twice as fast just to stand still - yes they report nominal numerical growth, but factor in population growth and they are more or less static.
It just isn't an attractive religion - otherwise they would be signing people up much faster - like say the Pentecostals or the Mormons even.