A lottery is generally defined as a promotion in which prize, chance and consideration are present. In order for a game to lawfully proceed, one of these three elements must be removed. A prize is anything of value awarded to winners, even if the value is nominal. This includes a cents-off coupon or a buy one, get one free offer. Certain non-tangible items such as bragging rights, special mention, etc., may not be viewed as prizes.
Chance means that winners are selected by a random process.
Consideration can be defined in a variety of ways but takes on two basic forms. First is monetary consideration, which would be the purchase of a sponsor's product or other kind of payment. Non-monetary consideration is an expenditure of considerable time or effort by a consumer which benefits the sponsor in some direct way. This includes such things as store visits and lengthy questionnaires. All lotteries, except those which are state operated are illegal under federal law and the laws of all fifty states.