From where I sit, you can’t actually “sell” an ebook
This comes up often and I grit my teeth every time.
You can’t have a discussion of any length about ebook sales and pricing and DRM in any sized group of digital publishing observers before you hear that it is somehow wrong or unfair that a “purchaser” can’t do everything with an ebook they’ve bought that they do with a print book they’ve bought.
That is: various “controls”, sometimes deliberate (DRM) and sometimes circumstantial (tech doesn’t always work smoothly) make it hard or impossible to lend, give, or re-sell an ebook in the same way that you do a printed book. Have enough of these conversations and you will become educated about “first sale” rights, which are enshrined in law, which basically say that when you buy something you own it and can lend, give, or re-sell it.
So the way the complaint often goes is that those damn publishers are putting this damn DRM on my ebooks so I can’t do all the things with them I can do with my print books.
This has always struck me as highly questionable on its face.