Tipping points are "the levels at which the momentum for change becomes unstoppable."<1> Gladwell defines a tipping point as a sociological term: "the moment of critical mass, the threshold, the boiling point."<2> The book seeks to explain and describe the "mysterious" sociological changes that mark everyday life. As Gladwell states, "Ideas and products and messages and behaviors spread like viruses do."<3> The examples of such changes in his book include the rise in popularity and sales of Hush Puppies shoes in the mid-1990s and the precipitous drop in the New York City crime rate after 1990.
source: Wikipedia
