"Dr. Gallup knows the thoughts of millions of people he does not know. This is how a French newspaper evoked in 1939 the extraordinary power of a new scientific method, which had appeared a few years earlier in the United States and was made famous by George Gallup during the American presidential election of 1936: the opinion poll. Mathematics proves it: it is enough to question a "representative" sample of a few hundred or thousands of people to know with precision the thoughts of millions of others. Nearly a century later, this scientific discovery is still perfectly relevant and new polls are conducted daily in the fields of politics, health, research or marketing.
Since the first face-to-face surveys, the various technological revolutions of the telephone and then the Internet have transformed the way
of collecting opinions. The last two decades have been marked by the emergence of the cell phone and by the exceptional development of social networks. Not surprisingly, surveys are nowadays also conducted via questionnaires adapted to cell phones and distributed through social networks in an automated way. Thus, 4.6 billion social network users around the world are now accessible almost instantly, ready to share their opinion on the subjects that concern them. For brands, this is a great opportunity in their quest to be ever more agile and ever more "consumer-centric", by adapting to consumers' expectations...
