Cool hunting is the frantic and efficient process of chasing the "hot", respected trends in the teenage culture. It involves surveys, observation, and sociological research.
An effective way to find a cool trend is to pay close attention to the trend-setters, the "head of the pack". They represent only 20% of the whole teenage target group and therefore are hard to find. But what they wear and do is desired and being strived for by the remaining 80% - your huge target group, a real gold vein of 30 million customers.
Once you nail down the cool trend, especially if it's still underground, you can market it, get all the profit you can out of it, mercilessly exploit it, and as a consequence, make it so widespread that it is no longer considered "cool". Thus, you find the trend, market it, and kill it. This is the basic of cool hunting.