American AAdvantage has a 40th anniversary promotion which runs June 7 through July 17 where AAdvantage members with co-brand credit cards issued by Santander Bank in Brazil earn about 5 miles per dollar.

The offer is “For every R$40 purchase on your Santander / AAdvantage® credit card, you earn 40 miles.”

• 40 Brazilian Real is about US$8.
  
• Since 40 Brazilian Real earns 40 AAdvantage miles, that’s 5 miles per dollar spent

There’s a lot of confusion around this promotion.

• Some people are reading this as 40 bonus miles per transaction that is 40 Brazilian Real or more

• While others are reporting that Santander Bank explains the bonus as “equivalent to the amount spent in reais, as long as the purchase is above R$40. Example: spent R$80, earn 80 bonus miles.”

In fact it’s better than either of these two interpretations. I checked with American Airlines, and after checking with the international co-brand team they’re confirming, “1 mile per R$ spent instead of 1mile per $ spent. …It doesn’t matter whether the total spend is from lots of smaller transactions (under 40 R$) or fewer larger transactions – it’s the total spend on the card at the end of the promotional period that dictates the bonus.”

In other words for every 40 Brazilian Real spent during the promotion period, 40 miles will be awarded. That’s unlimited earning of 5 AAdvantage miles per US dollar spent for over a month using the Brazilian AAdvantage co-brand. At most a little less than $8 worth of spending might get ‘stranded’ earning less than 5x. This is one of the richest credit card promotions I have seen, ever, at least that wasn’t based on a mistake of sorts.

I do have some Brazilian readers, hopefully this is helpful to them. Mostly I’m interested in it because it shows what is possible and even possible for a U.S. frequent flyer program. It also sets the bar for what we ought to expect from a big promotion, and we ought to expect partners with relationships big enough to support a $10 billion mortgage on the program to deliver promotions like this.