You could probably do better than 1% cashback.
If you want pure cashback, the Costco card, Fidelity AMEX/VISA, and others can give you more than 1%.
However, since you fly United, have you thought of getting a United card? Or maybe a hotel card to earn points? If you redeem miles/points for > 1 cent in value you are "earning" more than you are now.