A sweepstakes, also called a giveaway and a campaign, is a promotion in which prizes are given to winners selected only by chance from the entries received. Giveaways do not require a purchase otherwise they would become a lottery (which requires a license to operate), and are different from contests, which are considered a game of skill.
In sweepstakes, multiple brands (capped at 8) partner together to create a landing page and prepare a prize. Each brand shares it with their audience, and anyone who enters for a chance to win agrees to receive marketing communications from each brand. Each brand can then market to these entrants, converting them into readers or customers.
A good giveaway results in 3 things:
1. The entrant is excited about the potential to win a prize
2. The entrant is enticed to visit your website, try your product or service, etc. from a well-designed landing page
3. The marketers gain a valuable new lead to which they can send communications.