Delta needs to realize this crap alienates customers. Nobody likes hearing about it on the PA, and nobody likes getting them pushed in your face in the terminal. It is supremely annoying. Its like getting pestered by telemarketing and you feel trapped.
The credit card sucks. Sure it comes with some free perks but those wear off fast. Later on down the road when it becomes a headache with having another card, another bill, fees, etc, the customer is going to look at that Delta logo on it every single time they think of the card.