Delta is starting to reintroduce perks to it’s SkyMiles frequent flyer membership. This move isn’t seen as a benevolent one, but a competitive move against its competitors. The biggest upgrade is premium seat upgrades for free. American is seen as the main reason, since they have moved to allow higher paying passengers with elite status to those seat changes. Delta is hoping to pull away though high paying customers from an increasingly less competitive market.
Delta Brings Back Complimentary Upgrades for Frequent Flyers — Business of Loyalty