As a diversion, I’ve recently been entering sweepstates on SweepstakesToday. (This site is a portal to number of other sites that offer on-line sweepstakes).
On most of the contest entry forms, they have a required field for your date of birth. I can understand them wanting to know your age, so that they can send you age-related junk mailings, but why do they need to know the exact month and day?