This may have been mentioned before. I have always preferred Costco over Sam's Club because Costco accepts my Amex Delta SkyMiles card. Sam's only accpets Discover.Yesterday I purchased (with a credit card) a "shopping card" at Walmart as a gift for my son, only to find out that the shopping card can be used for purchases at Sam's Club. The lady at Walmart said they have been available for three or four years.I couldn't sleep last night thinking about the miles I should have been getting for purchases at Sams (computer,TV,etc)!