Having worked at a company that ran a lot of sweepstakes, I can tell you that Rhode Island, NY and Florida are often excluded from sweepstakes because of their onerous sweepstakes laws. Companies are required to register their sweepstakes and/or post a bond in these states with the value of the prizes to be given away. It's usually easier to just exclude those states.

Anyway, thanks for the tip on the sweepstakes!