Get rewards for inviting friends!
How? Simply send them your invite link and make sure they use it to download the game so you can get the rewards!
Triple (X3) the rewards when there's an Invite Friends Mania event!
Send out your links and make sure your friends install the game using your link!
Please keep in mind that rewards are only given to users who are completely new to the game, who download it via your link, and who then link their Facebook accounts.