I think the problem is, you're assuming:
Person A wants the book
Person A is willing to buy the book
Person A pirates it instead
The book was originally going to have a sale, but did not because of piracy
Piracy caused lost sales
When in truth, there are a fairly large number of cases where this happens instead:
Person B wants the book
Person B is not willing to buy the book
Person B pirates is instead
The book was not originally going to have a sale
Piracy caused no lost sales
But, Person B by pirating
did cause a lost sale. He has a copy of the data and he did not pay for it.
If I go into Borders, look at a copy of Ptolus but I'm not willing to pay the price, stuff it under my coat and leave, I have stolen it. I have the book to read or whatever and I haven't compensated the merchant, author, whatever.
If I decide I don't want to buy Ptolus and download the files off of a torrent, I have the data and I haven't compensated RPGNow or Monte Cook.
While this is "copyright infringement" and not theft, the only real difference between the two is that in the second case the data is on my hard drive and not on my shelf.
Why is the latter acceptible but not the former? Does it really matter what my
motivation is? Does it really matter what
form the data takes?
I'm actually not arguing about N0man's claim about the morality of purchasing a book and acquiring a digital copy too. That, I think, is a separate argument about having data in multiple forms.
And, yes, Simon, I run a moral game. I am a moral and honorable person. My job depends upon it. I'm sorry you find the concept of honor in the real world foolish. your loss.