Board Thread:Tips, Tricks, and Questions/@comment-183.90.103.156-20130718183817/@comment-186.151.62.77-20131018202654

The friend/person who downloads the game and uses your referral code must log in with their facebook account. Once they do so, when they are asked to choose a name, there will be an option underneat where you can type in the referral code. If that person doesn't log in using their facebook account, the option to type in the referral code will not show.