Be careful with adwords coupons. I've unintentionally spent about $600 on automatic payments by using adwords vouchers. I just needed to do a couple of one off campaigns so grabbed a couple of coupon codes and set up 2 new adwords accounts. As they were one-offs I used my wifes credit card to activate the accounts - wrong I know. Apparently all accounts opened with a coupon default to automatic payment, therefore racking up an bill at the daily rate that you set, even after the coupon is used. It would have been in the "terms" really reads them. So now my wife is screaming at me to get the money back. The accounts were set up in fictional names with all adds pointing to my money site. Theres no way I'm going to google (even if you could find a way of contacting them) and asking for a refund. There's also no way I'm contacting Visa for a chargeback and having anyone from Google see that I was abusing their system.