These three characteristics—one, contagiousness; two, the fact that little causes can have big effects; and three, that change happens not gradually but at one dramatic moment
Contagiousness, in other words, is an unexpected property of all kinds of things, and we have to remember that, if we are to recognize and diagnose epidemic change.
The Tipping Point is the moment of critical mass, the threshold, the boiling point.
All epidemics have Tipping Points.