'Diffusion is essentially a social process through which people talking to people spread an innovation,' wrote Everett Rogers, the great scholar of how new ideas are communicated and spread. Mass media can introduce a new idea to people. But, Rogers showed, people follow the lead of other people they know and trust when they decide whether to take it up. Every change requires effort, and the decision to make that effort is a social process.
http://www.newyorker.com/reporting/2013/07/29/130729fa_fact_gawande?currentPage=all















