Let me put forth this argument on Sprig's side, however.
Yes, electronic publishing doesn't seem to adversely affect paper sales. However, that MIGHT just be because we don't currently have an electronic reader that is as convenient as a paper form. Sprig, have you ever tried to read an entire book on a PDA? I have, and I eventually went and bought a copy--and it was a free book in the public domain! It's just too difficult right now.
If electronic paper does become big, I could see this being dangerous to the business.
However, there's the webcomic phenomenon to look at. They release their content for free, then expect people to support them anyway. How many people buy paper copies of webcomic books? It's a big industry--and those comics are all for free. Does that mean that because they're webcomics, Sprig, they're worse than paper comics? Just because free=crap?
Oh, and the research I quoted came--unfortunately--from one of the panels I attended at worldcon. So, I don't have anything solid to quote. There is, however, this argument:
http://www.baen.com/library/(P.S. You--Sprig--claim that by releasing his books for free, his later titles have become less popular. Why, then, does his first continue to sell so well? I argue that it isn't the 'free' nature that is making his later books sell poorly. It's the fact that he considers himself a 'literary' sf author, and is therefore writing works that are increasingly esoteric and difficult to read. People simply don't like the second two books as much.)
