Hey all! After we have received so many letters with questions like: "How can i get more coins...?"," I nead more coins!!!" 
We will give you an answer 
! In the current game version you can get coins:
1. Everyday about 20 coins for playing as a bonus!
2. For log in to the game with facebook (about 100 coins 
)!
To the future updates we will add the possibility of buying coins for real money! But now you are welcome tyo collect coins for free!
I need to get faceBook so i can buy Scorpion skin!
Where is.Facebook Login?
It got removed..
Now what?
Since this post was made on October 2015, eight months before even the Survival Multiplayer Server was released, what ever offer was made on here must've been discontinued many years ago
BlueTangs Rock3,
Unless they're talking about linking your PoC account with your Facebook account, which I believe is still an option either within the in-game's options, or the main menu screen's options.