http://www.mycokerewards.com/instant-wins/mcdonalds-arch-card-instant-win/26666
Click the rules link, then under section 5 click the link for free entry

17 Grand Prizes (1 per week): A $500 McDonald’s Arch Card. Approximate Retail Value (“ARV”): $500.
 120 First Prizes (1 per day): A $50 McDonald’s Arch Card. ARV: $50.
 2,880 Second Prizes (1 per hour): A $10 McDonald’s Arch Card. ARV: $10.

 Terms and conditions of Arch Cards apply. McDonald’s Arch Cards are not refundable and cannot be exchanged. Limit: 1 prize per person. Total ARV of all prizes: $43,300.

May 6 7:27 pm