Domino’s Pizza started in the 1960s as three small shops in suburban Michigan and has grown into the second-largest pizza franchise in the United States, behind Pizza Hut. The company has been riding a wave of global success, currently operating in more than 80 countries and delivering more than one million pizzas a day. Russell Weiner, the U.S. president of Domino’s, appeared recently on the Knowledge at Wharton show on Wharton Business Radio on SiriusXM Channel 111 to talk about what it takes to keep the humble pie a hot product in the ever-changing food industry. Weiner was also a speaker at the recent Retail and Consumer Packaged Goods Summit in New York. The event was organized by Knowledge at Wharton, Wharton’s  Jay H. Baker Retailing Center  and Momentum Event Group. An edited transcript of the conversation appears below. Knowledge at Wharton: Domino’s customers can now order online using an emoji. How did that concept come about?…