Got this in my e-mail:
extra 20% off already reduced prices at the Secret Sale!
Promo code: secret

seems like the usual brand exceptions apply. Doesn't look like it requires a minimum purchase or use of macy's card.

Secret Sale & Weekend Sale end March 15, 2009, unless otherwise noted.

*From March 11-15, 2009, save an extra 20% or 15% on your online purchase! Place qualifying items in your shopping bag, then enter promo code SECRET in the box labeled "HAVE A PROMO CODE?" and click "APPLY." Extra savings are reflected at checkout and apply to sale, clearance and regular prices, with exceptions listed. EXCLUDES: Specials, Everyday Values (EDV), super buys, bridge & designer shoes & handbags, kids' shoes, cosmetics & fragrances, O Bracelets, sunglasses, watches, electrics, electronics, furniture, mattresses, sterling flatware and toys. ALSO EXCLUDES: All-Clad, BCBGMAXAZRIA, Coach, Dooney & Bourke, Polo Ralph Lauren, DKNY, Emporio Armani, Henckels, Impulse, 7 For All Mankind, Ed Hardy, Lacoste, Martha Stewart Furniture, Tempur-pedic, Tommy Bahama, Tommy Hilfiger, Tumi, Wacoal, Waterford and Wusthof. Not valid on: previous purchases, specials orders, services, gift cards/electronic gift cards, payment on credit accounts. Cannot be combined with any savings pass/coupon, extra discount or credit offer, except opening a new Macy's account.