The Fine Print:
Expires May 19, 2011
Limit 3 per person. Limit 1 per order. Must order online. Must provide email address upon redemption to receive unique PIN and URL; you will not be added to Domino's mailing list. Carryout only. Valid at all US locations except those in Alaska or Hawaii. Not valid with other offers. Tax not included.
P.S. I keep a Groupon link over there on the sidebar (to the right) in case you ever want to get there quickly and check out the day's deals!