The "Every e-book sale is a lost p-book sale" belief of the BPHs, is a little odd, in the business sense. They must see a number of things that make for lost sales, how they respond to them means a lot.
Every competitor's p-book sale, is a lost sale. So, the need to gain market share, maybe lower prices.
Bad customer servicing results in lost sales. Appoint or Fire a director of customer relations. Take it more seriously.
A competitor's product has features that are more in demand than the features on our product, which leads to lost sales. We need to beef up Product Development, find some new talent.
Misdirected marketing leads to lost sales. Find out who wants our product and how to reach them. Do, or better yet, pay for a market study.
How are they responding to the Idea that "Every e-book sale is a lost p-book sale"?
I have no answer, just the perception that their response has not been effective, (or perhaps even rational) and that they would just as soon ignore the existence of e-books.