title_body: What is the difference between giving away my only print copy or my only electronic copy of a book? The question If a book doesn&#39;t have DRM does that mean it is OK to give a copy to my friend to read? has answers implying that without permission there are legal and ethical hurdles in giving away a copy of an ebook.  In the United States, there are stores selling used books, which are under copyright.  
  
  As Harvard Law School buys back used text books, presumably with the intent of resale, it is probably safe to assume the action is not illegal, in the US.  
  
  It seems that selling or giving away your copy of a print book that is under copyright is a not a problem, so how is that different than doing then passing on your only copy of an ebook, assuming you delete the existing copy on your device?
upvoted_answer: There are a couple of key legal differences between print books and ebooks:
  
  
  First, ebooks generally are not purchased, they are licensed. If you "buy" an ebook from Amazon, you don't actually own it--you're just allowed to use it.
  Second, there's the First Sale Doctrine. This is what allows owners to sell print books when they're done with them. At present, it's unclear whether the first sale doctrine applies to digital goods, but the courts seem to be leaning away from letting it, meaning that selling your ebooks when you're done with them is not likely to happen. There's a good writeup on this available here: https://library.osu.edu/blogs/copyright/2013/04/23/the-first-sale-doctrine-and-the-sale-of-digital-goods-in-light-of-kirtsaeng-and-redigi-inc/. A relevant excerpt (talking about reselling digital music files, but probably indicative of thoughts about ebooks as well) is:
  
  
  
    Capitol Records brought suit against ReDigi on the grounds of
    copyright infringement. The United States District Court for the
    Southern District of New York held that ReDigi’s website infringed
    Capitol Record’s rights of reproduction and distribution, and that the
    distribution of the digital music files was not covered by the first
    sale doctrine. The court reasoned that the process of creating a copy
    of the work on ReDigi’s cloud server was an unauthorized reproduction
    (the first sale doctrine applies only to lawfully made copies that are
    distributed, not reproduced) and that because an additional copy was
    made for the server, users did not distribute or sell the particular
    copy that they had originally purchased.
  
  
  As much as we may think they are basically the same thing, ebooks and print books are quite different in a number of ways, and we're still all figuring out the nature of those differences, let alone how to deal with them. It may well be that the entire business model changes enough that the first sale doctrine becomes irrelevant to ebooks&mdash;if ebook subscription services become the primary method of distribution, for example.