I recieved an American Express Gift Card as a...gift. It says mostly how to use it but I still have a question. On one of the many instruction sheets it does say I can use it at online vendors, but it does not say how. In the past I have seen one, that I can remember, online vendor that had the option to pay with a gift card, aside from regular credit card payment. Can I only buy online from sites that offer this option, or am I missing something. It seems they avoid the topic in all the instructions and online, just telling me I can, but not how to...Thank you.