Just found out about this the other day from a friend of mine. If you buy a game digitally the game comes with two licenses (one tied to the account that purchases it and another to "lend" out). He was already sharing with another friend and got 6 games off of him. Now i just need to find someone to give me their games in exchange for mine lol.
source on xbox.com : http://support.xbox.com/en-CA/xbox-one/games/my-home-xbox