HI Neopatrick,
Really interesting insight Costco rebate card...I was very lucky in that I have a green Costco Small Business Corporate Card...can't get them anymore but I get credit for all purchases at Costco cause it is a AMEX card...plus because it is a AMEX card I can add on family member/employee cards and for a small connect fee I get Amex miles for all the purchases they buy too.

I know others have c/o taht AMEX is not accpeted everywhere..I fid that to be reare in the places I go..but I do have a MAstercard back up...might be switching tho too...