I recently built the gold mine and it seems to be working pretty good. You get 10 gold daily from each player you add in Facebook. I created a group in Facebook to make it easier for players to find and add each other. This also provides a way of communicating and share info about the game. I cannot post a link here but if you search for the game under groups you should see it come up. The group is called World at War WW2 Strategy MMO Gold Group. All members in there play the game and are active, feel free to add them to gift and receive gold daily.
Gabriel Diaz