Just received an email with what appears to be a unique code for $10.
*Extra $10 off your purchase: Offer valid from 1/15/2018 at 12:00 am ET to 1/27/2018 at 11:59 pm ET online and at Gap, GapBody, GapKids, and babyGap stores in the U.S. only (including Puerto Rico). Not valid at Gap Factory/Outlet or on GiftCards, packaging, shipping & handling, taxes or prior purchases. The dollar value of the Shopcard allocated to an eligible purchase (or to any item therein) will not be returned or refunded if the eligible purchase or applicable item is returned or exchanged. One-time use only. Unused value will be forfeited. Not valid for cash or cash equivalent. Discount taken at register in stores. Online & in store: enter promo code at checkout.