Win notifications usually arrive by email, postal mail, registered mail, telephone, or social media. It's important to make sure that you check the contact methods you use on your sweepstakes entry forms regularly; it's devastating to miss out on a big prize because you waited too long to check your email!
Winner selection in a sweepstakes is conducted in an unbiased manner to give all entries those with and without an order an equal chance to win. This is usually done by a random drawing or a preselected number.