Yeah.. I was pondering about how UA has set up and how they're monitoring these card number(s).. I assumed they got help from their good buddies at Chase, but I did a search on the BIN (bank identification number..which is the first 6 digits of any Visa or MC) for the MasterCard, 555027, and it's a Citibank corporate purchasing card. So Chase isn't involved. I wonder if they're issuing a separate card number for each purchase with a $100 credit line and it gets closed after one purchase? Or if there's one master account that is restricted for use at just one merchant.. GOES, or if there's a master account with a $100 single purchase limit..many possibilities. Either way.. managing something like that has to be difficult. There's risk involved with passing out credit card numbers.