Yes, it is a bonus. Having the pdf online also prevents me from needing to walk 500 yards to the library where I can also find it for no cost. But seriously, I

Yes, it is a bonus. Having the pdf online also prevents me from needing to walk 500 yards to the library where I can also find it for no cost. But seriously, I think it's safe to assume that Mr Skolnik [1] is doing just fine. Given that his publisher is likely taking the lion's share of the proceeds, and that generally speaking, writing books for academia is not a profitable enterprise, I have no problem using a found pdf or finding the book in the library. I know personally several academics who have written books and they do it to solidify their expertise and/or obtain tenure, not to make money directly from sales. Hence the movement to give books away for free [2]. [1] https://en.wikipedia.org/wiki/Merrill_Skolnik https://en.wikipedia.org/wiki/Merrill_Skolnik [2] https://open.umn.edu/opentextbooks/About.aspx https://open.umn.edu/opentextbooks/About.aspx