This has worked for me as well. I used up the $100 already and tried creating another account to use another cc which is needed at time of your ad going live.. unfortunately they banned my new fb account within 48 hours

btw there were also three $50 coupon codes floating around some blogs that gave you a total of $150 on top of the $100 but these have stopped working now.

As far as I'm aware, the $100 at sign up is still working. You need to add the Visa app to your FB account and then within an hour you will receive the coupon code at your FB registered email address..