I believe this deserves it's own thread, only got it on one card (blue cash).
this is basically free membership!
Details
MUST PRESENT CODE AMEX25 (click “Print Confirmation” or show saved code on phone) at a BJ’s Member Services Desk by 8/31/16 to get 50% off ($25 off $50) a new BJ’s Inner Circle® Membership plus a $25 BJ’s Gift Card. Valid in-Club only. See terms below.
in the terms: is good for new Members only.