Ah. So the leaders can give the ongoing message to "give generously" to a group and, as long as the giving data is kept in secret and no one ever speaks to anyone else about how much they gave, then each member will feel compelled to continue to give more in an effort to (a) "please God" and (b) gain favor in the eyes of the leaders by keeping up with, or outgiving, the other members. Is this what you are saying? If not can you elaborate?
Look at Mormons. They have a rule that you have to donate 10% of your income. If you don't than you aren't pleasing god and god might punish you.
In reality the average Mormon doesn't donate 10% but might feel guilty for not doing so. If someone who would donate 7% would know that they donate above average, they would feel less guilty about not meeting the goal of donating 10%.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.