Wait, what?! You haven’t put up any Facebook contests yet this month? No worries! SociallyStacked has 12 really easy contest ideas that you can implement in minutes. They analyzed more than 50,000 active Facebook Pages and 300,000 custom Facebook Page apps that serve more than 1.4 billion Facebook fans and, among the things discovered: Engagement in December increases by as much as 66 percent on custom Facebook Page apps. More below.