You will be automatically entered to win the $150 raffle just by tweeting about the Tweet2Win.com. Raffle is for a $150 gift card from Amazon, eBay, Victoria's Secret, iTunes, or Overstock.com. You can even increase your chance of winning by blogging about the site.
Apparently there's no catch. The site gets free promotion and traffic while Twitter users play their chances for a prize. A winner is chosen every week and for a different prize. And as Mashable said, "basically it’s a marketing gimmick that attempts to leverage Twitter, make money out of exposure, and essentially create a sort of user-generated advertising spam."
Follow Mashable on Twitter at www.Twitter.com/Mashable