Today, it's unlikely Donohoo will be the first to say hello in a group setting, but interacting with people is easier for him than it once was.

CNN: One man's story: When an autistic child grows up

As the former head of the International Atomic Energy Agency, he won the Nobel Peace Prize for the group's work in nonproliferation and has had a long career interacting with global leaders in international capitals.

WSJ: In Upheaval, ElBaradei Is a Wild Card

For established brands, the format provides a direct way of interacting with customers, turning each day's trading into a consumer focus group.

ECONOMIST: How an alternative trend went mainstream