Originally Posted by Bluebirdie

Similar experience happened to me before. I added the offer via Twitter and received Amex notification plus email confirmation. The offer also showed up in my online account at the time. A few weeks later, I had forgotten the promotional dates. So I logged into my Amex account to check the dates and found the Amex offer gone. It would not allow me to add it again, yet it's not showing up in my added offers neither. Although I had the email proof, I decided against Amex and used another card instead.

I got so paranoid now I check the offer in my account before I use it.... whenever possible. Some Amex offers are decent and worth the effort. Others are not.