It turns out that United’s mystery double miles promotion that Northwest was ostensibly countering with its own double miles promo was a targeted email offering to Mileage Plus members in the Upper Midwest.

United was certainly targeting Northwest’s stronghold, just days after Northwest mechanics went on strike. Northwest countered with across-the-board double miles.

While United was taking advantage of an opportunity to poach Northwest passengers, I suspect Northwest is trying to lure passengers who might otherwise book away due to negative publicity surrounding the strike in a month where traffic is likely to be slower than the peak summer season.