title_body: Kindle Cloud Reader can't open this book
upvoted_answer: The Kindle Cloud Reader is a Kindle Web App which anables us read Kindle books online.
  
  As my own guess, Amazon use this web app to allow us to read kindle books online, and most of those contents are Kindle manga or comic. 
  
  For those long-text kindle eBooks(such as novels), we are limited to use Kindle desktop app or Kindle devices.