Maximize Frequent Flyer Miles: Seek special deals, read the fine print
Northwest runs promotions called Cash & Miles, which can yield better deals than its PerkChoice program. Note that these offers are often restricted to certain credit card holders. Delta, for instance, makes such promotions available only to SkyMiles members with a Gold, Platinum, or Reserve Delta SkyMiles credit card from American Express (the parent company of Travel + Leisure). Finally, be aware that the miles you will—or won’t—earn are a factor in the “real” cost of the trip. United’s Choices program allows you to earn miles for award seats, but Delta and Northwest prevent you from upgrading or accruing miles for award-ticket travel (though Northwest will now allow you to rack up miles and purchase an upgrade on the leg for which you pay cash). While crunching the numbers is more subjective than ever, at least now you have some options for spending a little less (in miles) in exchange for certainty.