The last time the CO was around, about 10 minutes of one of his talks was essentially about how congregations "in western countries" sometimes don't contribute enough even to pay for the cost of their literature, while congregations in poor african countries are giving their last cent to pay as much to the org as they can. "How sad a situation it would be if those poor brothers in africa where subsidizing our magazine costs" he says. He never stated that it was a problem locally (I did an accounts audit not long ago, and I'm quite certain it's not). It was all sort of implied in a way that it seemed to be designed to give the impression that we weren't giving enough while not actually giving any information about how much we should be giving, or how much was currently being given. Clearly the goal was to get everyone to give more, regardless of whether they were already pulling their weight or not.
I've also noticed that when I was in poorer congregations, they would frequently name a dollar amount as a per-publisher monthly figure to give us an idea how much to donate, but in the congregations in better neighborhoods, they've never done this. Instead, they just make this type of generic plea for more money and throw out hypotheticals about what that money may be used for. My guess is that in the poorer congregations, most aren't pulling their weight, so the average figure is above what most are giving. In the better off congregations, they can't name a figure, because most are already giving more than that so they might actually reduce how much they get if they say how much is needed.
Another option, is that they per-publisher figure is more effective in congregations that have more large families (these also tend to be the poorer congregations) because there's probably a tendency for those folks to translate per-publisher to per-person and therefore donate for their young kids too.
When you start to see how things get treated differently from place to place, you can really see how money-grubbing the cult is.