title_body: Is it time to do away with (e)book return policies?
upvoted_answer: This is probably not the best kind of question for SE because it asks for an opinion, and your needs may vary. 
  
  Also, there are technical issues and business issues involved.
  
  Also, I'm guessing that you are talking about non-DRM files. If you had DRM in your reading system, it would probably be trivial to revoke the license for a piece of content. 
  
  I start with the assumption that most people are honest and that returns happen rarely in ebook sales. I also start with the assumption that piracy is not a significant problem for most ebooks. 
  
  It would be good customer service to allow returns. It defies expectations when you say that all sales are final -- especially if the customer made a mistake. 
  
  A more common issue is that the user purchases something and then discovers that the ebook has significant formatting issues or doesn't render well on the device he or she is using. 
  
  My approach would be to allow the return, but set limits on how often a customer can do it. Also, I would limit the window of time which customers can return things. 
  
  Purely from a business perspective, book purchasers are a rare enough species that I wouldn't do anything to alienate them. Also, aside from time and inconvenience, the ebook seller doesn't really lose the good because it is not a physical object. (That's why when I publish things, I am liberal about sending out review copies -- it costs me literally nothing).