The idea is simple. You go to their site, they have 3 special offers and you vote on which one you would like to have an opportunity to buy.
Amazon.com then randomly selects people to have a shot at buying one of those items. If you are selected, you have to join the race to be one of the lucky ones.
Last year I got a Nintendo Wii for something ridiculous like $99.
Have a look, it might help you save a little money this Christmas time!