Given how easy it is to make copies in this day and age, I don't think that's a necessary link -- but you're probably right. My assumption in any case is that a given child porn image is consumed thousands of times, so the effect on the consumer end would dwarf the effect on the producer end.

This argument is easy to turn on its head (just goes to show how easy these kinds of arguments are to make). If copying cp is easy, the same item is more difficult to sell multiple times. This creates an incentive to produce more material, because nobody is going to buy material that is easy to copy for free. Old material is more available for copying than new material. As was already argued, producing cp creates more abuse. In any case, there's always going to be demand for novelty.