Sublime

the most habit-forming products and services utilize one or more of the three variable rewards types: the tribe, the hunt, and the self. In fact, many habit-forming products offer multiple variable rewards.

accumulate wealth,

“Do you make your users feel accomplished?”

Core Drive 5: Social Influence & Relatedness.

This is a field known as gamification,

Progress metrics like points, badges, levels, leaderboards, and reputation systems are icing on this learning/mastery cake. These markers help you gauge where you stand, and how far you’ve come—but they’re meaningless as a stand-alone system without something to master. If you want to build a compelling product experience, forget points—think chara

Feedback Mechanics and Triggers.

Appointment Dynamics (Game Technique #21)