title: Facebook app special gifts implementation?
body: <p>Example: Bejeweled Blitz frequently runs events and promotions that, when clicked, take you to their app page. Once there, the app can see that the page was reached by following the promotional link and forks over the reward.</p>
  
  <p>How is this done? What do I need to do to implement a similar feature? To my knowledge the parent URL is out of bounds due to the domains being different (Facebook vs. my app), so how is the message passed to the app?</p>