How to :
1. Go to GodFather page.
2. Scroll down and you should see an offer from Visa for 2 free Reward Points.It's a one question survey.
3. Watch the video clip that pops up. Finish the survey and when you go back to the game, you will have extra 2 GF.
But I notice not every players have this offer.
Not bad for free GodFather points.. Good luck!
PS : Thanks to Edmund Lee for the info!