“Endorphin branding.” That’s how C. Russell Brumfield characterizes scent marketing, which is starting to proliferate due to technologies that can embed scents in consumer products large and small. Brumfield, chairman of WHIFF Solutions and author of “WHIFF – The Revolution of Scent Communication in the Information Age,” was a keynote speaker at this week’s Scent World Conference in New York. AdAge.com spoke to him about where scent marketing is headed.