We become habitual users of games , apps and services when they hit that singular “sweet spot” of opportunity, need fulfillment and social context. My son, for example, NEEDED to be on Myspace, then Facebook – and now Snapchat. His daily … In my next 3 posts, I'll explain these design rules in more detail, illustrated with examples from Minecraft, Lumosity, Duolingo, Facebook. Twitter, Instagram, and Clash of Clans. In the meantime, please share your thoughts