Promoting a Site with Cash Giveaways

I have seen people crazy about solving crossword puzzles or Riddles in magazines or news papers, as a hobby or to get a cash prize. They help to promote the sales and attract new subscribers. Likewise, many websites announce Cash Giveaways either to promote business or to introduce a new product. Recently, I peeked at an interesting cash giveaway thread posted in a famous site. The task is to answer a question and the prize money is $15 for winner and $10 for runner. The question is “If you are provided $ 100,000, how would you invest that money to get best returns over 3 years?”  Almost 50% of the participants answered that FOREX trading will be a highly profitable investment.