Earlier this week Zynga launched their newest game Frontierville - it already has 1.3m monthly actives and 450k fans. While Frontierville's gameplay inherits many of the best practices of its siblings, its domain behavior doesn't. Zynga has made an effort to instill their own branding across the properties and place games at their own domain - like Farmville.com (screenshot at bottom). Frontierville.com however behaves differently. Rather than its own domain and embedded gameplay, it uses a frame to display the Facebook application page while maintaining the frontierville.com domain. The page itself is grayed out - but still active (showing your Facebook data and playing the Frontierville music). The page isn't actionable... but when clicked (anywhere) you are directed to the actual game and application page: http://apps.facebook.com/frontierville/

Here is Farmville.com: