My experience (creating PDF ebooks at gmathacks.com) has been similar. I probably get an email every 2-3 months asking about a printed copy. I have a standard

My experience (creating PDF ebooks at gmathacks.com) has been similar. I probably get an email every 2-3 months asking about a printed copy. I have a standard response re: benefits of the PDF & one's ability to create their own print copy, and nearly all of the inquiries result in the sale of an ebook. I'm probably losing a handful of customers who don't email me in the first place, but that's an ok tradeoff for me in that it spares me the hassle of setting up a print-on-demand deal and (I irrationally fear this) inevitable customer service issues that arise from having to physically ship stuff (even it's a turnkey operation and somebody else is doing the shipping).