The interactive landing page that is virally promoting itself

I'm one of the creators of the the landing page that we launched recently while the product is still in development. The landing page has an interactive twist that gives people an incentive to share about us.

In the time its been up we've seen the majority of visitors coming back to the page several times, interacting with us a long time each visit and sharing about us on Facebook and through personal referral links. In addition we have seen a strong percentage of referrals coming back to sign up.

Along side to traditional email sign up using Launchrock we added an interactive element that gets visitors a reason to share and spread our message for us and increases our traffic. But in addition people are staying on the landing page for significant time, coming back multiple times and telling us that the game is addictive.

We used a modified game tied to a giveaway where a higher score gives a higher chance to win an awesome ski trip for 4. People are entered by filling out an email prompt after they've played a bit. They get to play longer, so they can get to a higher score by sharing on Facebook and by having their friends come play the game once they run out of lives. So far looking great like a snowball picking up steam.

Would love to hear HN's thoughts!