The current cost of writing software is zero.
This will sound weird to them. It sounds weird to me. I think they will immediately say "of course it does, programmers need to be paid", etc. and will be distracted from the point. "Unlike industrial processes there is no inherent cost to software development. A programmer does not need to supply raw materials in order to build a program since a program is an expression of an idea. ** In this sense, at least, programming is more like mathematics than industrial processes since the value in the program is only in the way it expresses the ideas of the programmer **
(I'm not too thrilled with the text between the "**" markers)
Glenn Strong
It'd be better to compare programming to writing a novel, a more familiar concept.
<Rory>