Wildfire is a cool application for promotions, sweepstakes, contests and the like. It doesn't cost anything to sign up, However there is a cost per campaign.
The Benefit of using an application like this is that you can make your contest go virual through a number of social media platforms, this than increases your following on your fan page.
Face Book also has a free alternative called promotions, If you go to edit your page and then applications you will see promotions.. any problems, give me a yell..
Enjoy
Leanne