Use this link to add your American Express card to your Facebook account:
Link: http://www.facebook.com/americanexpress?sk=app_216352075054740
Click the offers to add them to your account.
Here's a few of the offers:
$10 statement credit when you spend $100 at Best Buy
$2 statement credit when you spend $10 at Burger King
$5 statement credit when you spend $20 at Whole Foods
Free ground shipping at NikeStore.com (use with all the coupon codes they've
had recently)
$300 statement credit when you spend $2000 on Celebrity Cruises
Small Business Saturday spend $25 and get a $25 statement credit.
There are a lot more, just click on See More at the bottom of the grey box.