**This is not meant to be the definitive basis or way of calculating the society's earnings each year, but just an observation.
From my congregations accounts, I averaged the last six months of what is sent to the Society just out of curiosity. That amount is approximately $620 per month. Now, my congregation is located in what is known as a relatively poor town in the U.S. I understand that many congregations will give much more than this and many congregations will give much less. For the sake of argument, let's assume that the figure listed above is approximately an average of what the Society receives per congregation.
Multiplying that number by the 103,267 congregations worldwide.... $64,025,540 PER MONTH.
Yearly that would be $768,306,480. And that is not including donations sent directly to the society or received at assemblies or conventions.
Of course, again, this should not be looked at as a be all, end all number for seeing what they rake in just from a congregational stand point...
And I'm sure someone could locate a financial earnings statement online somewhere, but I thought this would be at least an interesting perspective on things.