I have noticed something on the website of Continental that kind of boggles my mind. As I am always looking for good deals to fly to Canada, I was searching fares. As it turns out, if you pay with a Canadian credit card, the flight is almost 500 dollars more expensive than if you pay it with a Brazilian credit card.
Try it yourself, when paying with a Brazilian issued credit card, the fare is 1265 USD plus taxes,with a Canadian credit card,it costs 1707 USD plus taxes.Just go up to the top right corner and change your billing country.
I used to fly on Air Canada,but their connecting flight from Sao Paulo to Rio is very inconvenient, whereas Continental has a very good schedule between Calgary and Rio de Janeiro via Houston, AKA the 'petroleum milkrun'.