OK OK, I'll tell you. When you hit $50.00 in your account Google automatically mails you a PIN # to the registered address. Once you receive it you enter it in your account. This must be done before you are issued any payments.
PIN is "Personal Identification Number" mailed to your postal address, for the safety & verification of publishers' address. This process is required only once.
Just to add in some info. PIN postcard may take time to arrive so be patient. And if does arrive in a month, you can apply for it again after a specified time(about a month). I got my PIN after a wait of 2.5 months. Be patient, that's all i can suggest _____________________________________ Always there for friends