Recently, my husband and I were flying home out of Syracuse, NY and got stuck overnight because our departing plane never arrived due to "weather conditions" in the northeast. United did not provide any hotel vouchers, since the delay was weather related so naturally I got on the phone and booked us into the nearest Marriott (which turned out to be not all that close and did not have an airport shuttle). I was happy thinking we could use the cat 1-4 certificate from my credit card, but when we checked in was told that needed to be pre-arranged over the phone. Since we were in no mood for more hassles we just put the room on hubbys Marriott Visa card.
In the back of my head I knew that my United MasterCard has some travel insurance included with flught purchase. Once I looked into it I could have kicked myself. Had we used the United card we could have been reimbursed for the cost of the hotel room/ breakfast and the round trip cab fare, but since we used the Marriott card we were not able to take advantage of the insurance! I'm sure most of you are too experienced to make that kind of rookie mistake, but I thought someone might find it useful. ( The only other time I was stuck overnight it was due to mechanical issues, so I did get a hotel voucher.)