What a joke. You have the option to link your google acc & facebook acc for gems. Wow, great, we all need them. No mention that you can only have either google or fb but not both. So i used google until one day when i needed more gems (that's the catch isn't it?) and linked my fb account as well which automatically "erased" my google link to the game. Now i'm left obligated to have my fb profile linked and lose all progress (days!) in case.. i don't want a fb acc anymore? Lol, delete.