I go through this a lot too. I've bought books in ebook format that I've regretted, because I can't lend them easily. Conversely I've bought physical books which I wish were ebooks, because I don't reference them that often, and they're really wasting space. Not being limited to one or the other format would be great!
Although what happens when you buy the physical book, get the ebook for cheap, then on-sell the physical book? Seems like an open loop.
Yeah. Although that's an open loop with CDs that has existed for years, so I imagine Amazon has some reasonable notions on the magnitude of the problem. I'd guess it's much less of an issue with books; CDs have a much higher repeat use value than most books do.
My guess is that some people will do it accidentally, but that the number of people doing it as a book cost-reduction strategy will be pretty low. The net yield on selling used books is not good. And I'd guess further that for 98% of on-sold physical books, people will never go back and look at the ebook again.
It depends on the type of book. For fiction this is definitely true. For textbooks and technical books, there is a massive used market with high resale prices, which is more what I was thinking of. I suspect a lot of these vendors simply won't jump on the bandwagon without some kind of reassurance.
Although what happens when you buy the physical book, get the ebook for cheap, then on-sell the physical book? Seems like an open loop.