It is commonly thought that advertising is the key to creating demand. While advertising does make known the availability of products, it is often not the reason why people buy. People tend to buy from people.
Sociologist David Halpern notes that social networks are very important in driving markets:
“Even in the high-tech world of e-based world markets, it remains the case that most business continues to be channeled not just by price signals but by social networks. People tend to buy from and do deals with those that they know, be they farmers or city financiers, and the business lunch remains as ubiquitous today as ever. Today’s market is high-tech, but still ‘high touch.’” (David Halpern, Social Capital, Polity Press: Cambridge, 2005, p. 51.)