New Customer Discount - 25% off first box. Enter code WDFIRST25 at checkout before submitting order. Not valid on prior purchases. Only valid for first-time buyers. May not be combined with other offers. May not be used for gift cards. Not redeemable for cash. Limit one per household. Not eligible in all states. Void where prohibited. Offer ends 12:00 AM PST on January 1, 2018.