title_body: What are advantages of publishing DRM-protected books for an author?
upvoted_answer: Answering the opposite question, Tor books switched from DRM to non-DRM, and they commented (no figures available) that they saw 
  
  
    no discernible increase in piracy on any of our titles
  
  
  http://www.tor.com/blogs/2013/04/tor-books-uk-drm-free-one-year-later