For many social entrepreneurs, happiness comes from the feeling they are making a difference. In research for my book Evolve! , I identified three primary sources of motivation in high-innovation companies: mastery, membership, and meaning. Another M, money, turned out to be a distant fourth. Money acted as a scorecard, but it did not get people up-and-at 'em for the daily work, nor did it help people go home every day with a feeling of fulfillment. Viide: http://blogs.hbr.org/kanter/2013/04/to-find-happiness-at-work-tap.html