Starting epidemics requires concentrating resources on a few key area. The Law of the Few says that Connectors, Mavens, and Salesman are responsible for starting word-of-mouth epidemics, which means that if you are interested in starting a word-of-mouth epidemic , your resources ought to be solely concentrated on these three groups. No one else matters.

It's very hard to find someone who's successful and dislikes what they do.

Emotion is contagious.

Whenever we have something that we are good at--something we care about--that experience and passion fundamentally change the nature of our first impressions.

Anyone who knows the marketing world knows that ideas come and go, and people latch onto things and think of them as a kind of solution.

And my advice for college graduates is don't reflexively give money to your alma mater, something particular to Americans that I find extraordinary. Take Princeton, for example - it has more money on a per capita basis than any educational institution in the history of educational institutions. There is no scenario where it can spend all the money its endowment generates every year. If there is anyone who gives a single dollar to Princeton, they have completely lost their mind. I will say that without reservation.

Innovation-the heart of the knowledge economy-is fundamentally social.