I think you're missing my point and the point discussed in the article I linked to. Sure, the incremental cost is less (not 0, since places like Amazon may char

I think you're missing my point and the point discussed in the article I linked to. Sure, the incremental cost is less (not 0, since places like Amazon may charge an electronic delivery fee), but the total cost still ends up being very similar for the digital version, even accounting for the lower incremental cost. The incremental cost of a paper book is also almost nothing, so I'm not sure where you expect these savings to come from. Overall, ebooks are in fact often discounted more than the cost of printing the paper book.