I loved this feature when I had Amex. The unique number-vendor pairing makes it easier to track down the vendor that spilled the beans to the charge defrauder.

I loved this feature when I had Amex. The unique number-vendor pairing makes it easier to track down the vendor that spilled the beans to the charge defrauder. I was thrilled when capone started offering a similar service but its offering requires a browser addon with a backend anal about matching domain names to merchant names and sometimes rejecting valid purchases (I'm looking at you Dell factory refurb outlet).