You need a compelling prize, a recurring drawing, a database, and most importantly, a well-crafted email campaign as an adjunct to the contest. Manufacturers of unique and interesting items have the best chance of winning with a contest promotion. All web businesses must implement an effective search engine strategy. Very few businesses thrive from search engine traffic alone. It is only one of the seven promotional methods you should try.
Internet business is tough.
If you already have a great site and a compelling value proposition, you stand a chance. But if you are really serious, you must attend to promotion. Don't waste money. Test to see what works first. Then go for it - spend big money on promotion.