I always book through Costco. There is a Costco about 1/4 mile from my house, and I shop and buy gas there all the time, so the Costco Cash Card is perfect for me. The rebate is usually around 8 to 9% and you receive the Cash Card after you return from your trip. Like Sayhello mentioned, when you call the Costco Travel number to book an ABD, the call goes directly to a dedicated ABD rep and once you have booked you just call ABD if you need to communicate with them further.