Free $6 box of snacks from Graze.com – via an invitation code to try out membership in their food delivery service
“special invite code”: STGRZ
Note: It appears that you can easily cancel your membership as soon as you get the free box, and therefore not have to pay anything to them, but make sure to check out the rules before you sign up and know what you are getting into, since this appears to be a service that sends out boxes of snacks pretty frequently and then charges your card.
From the postcard: “For new grazers only. Valid credit or debit card required but your first box is free & you can stop deliveries at any time.”