American Express is offering a One Time $25 Statement Credit with $100+ Purchase at Costco.com. Offer valid thru December 31.
sync your Amex card to your Facebook account
If offer does not appear, after you enter your card information scroll down page and click "Load More Offers"
Click on the offer, then "Add to Card" and it will move to blue button that says "On My Card"
Make a single purchase of $100 or more by December 31, 2012
Non-Members pay a surcharge of a minimum of 5%
A statement credit should be issued within 8 weeks of your qualifying purchase.