Berger's STEPPS model stands for Social Currency, Triggers, Emotion, Public, Practical Value, and Stories. The power of the model is not that every viral idea has all six. It is that the more of the six an idea embodies, the more likely it is to spread naturally. Berger is careful to distinguish between what he calls immediate social transmission, the kind of sharing that happens right when someone encounters something, and ongoing word of mouth, the kind that keeps happening days, weeks, or months later. Immediate sharing is driven primarily by emotion and social currency: the thing is exciting enough, funny enough, or impressive enough that people want to share it right away. This produces a spike. Ongoing word of mouth is driven primarily by triggers: the environment keeps reminding people of the idea, so it keeps being discussed long after the initial encounter. This produces sustained spread. For anyone trying to make something catch on, the STEPPS checklist is a diagnostic tool. Go through each principle and ask: does my idea have this? Social currency: does sharing it make the sharer look good? Trigger: is it linked to something in the environment people encounter regularly? Emotion: does it generate high-arousal feeling? Public: is it visible when people use it? Practical value: does it help people in a concrete way? Story: is there a compelling narrative that carries the message? The answers will reveal where the idea is weak and what to change to make it more spreadable.