Does that mean that, I, being your best friend of course
, and already having an Amazon account should sign out my kindle (that I don't possess but it's for the demonstration's sake) and sign in with your account in order to read a book you, generously, lend to me ? Or is it a way to be signed in with multiple accounts on a kindle ? As far as I understand it, for the Kobo (Touch and Glo at least) you can be signed in just one account at a time.