The watchtower was masters at what is known as "stuffing the supply chain." For example every publisher has stacks of un place magazines and books, the congregation has stacks of magazines and the society had an a corresponding stack of unsold. And yet at the same time they would advertise the how much publishing as proof that they were in pursuit of the hearts of the honest hearted truth-seekers.
In reality campaigns were simply to relieve excess inventory. Or at least to shift the inventory to the hands of the publishers.
This is a very inefficient and costly system. It seems they have gotten away from this by focusing on web-based material.