For four decades now, William “Mack” O’Barr has taught an advertising course so popular students routinely are turned away. Now they’ll get another crack at it.The digital version of O’Barr’s “Advertising and Society” course debuted October 27 through the Coursera online education platform. He hopes word will reach alums who, years and perhaps even decades later, would still like to hear what he has to say on the topic.

Moments after Brad Brinegar told the staff of McKinney advertising agency that it would be moving from Raleigh to Durham, six employees came to him with some version of the same question: “Why are you giving me a death sentence?”