This deal has ended.
Ending today (10/10), and available only in stores Sam's Club is offering a seasonal 15-week membership good through the holiday season for $15. This membership allows you to make purchases in-store and online. An annual Advantage membership runs $40. You have to apply for membership in the store during normal store hours and this is the last day--so if you want to take advantage of this offer, you'd better hurry. More details on the membership are here.