You don't indicate where you are located in the US, but your location may influence your choice of one airline program to concentrate on. (Other factors, such as your preferred destinations for award travel are also important.) I'd suggest registering your Discover card with the dining program of whatever airline seems best to you, and filling out a profile at the website of that airline's dining program. In most cases, doing so will get you a 1,000 mile bonus. That's not a lot, but it's easy to get, and the dining miles keep your account active.