Summer sale: Save 58%

Colleen P. Kirk

FILE - In this Friday, Nov. 27, 2015, file photo, cousins Stacy Levine, left, and Melissa Bragg shop at a Toys R Us store in Atlanta on Black Friday. ((Bob Andres/Atlanta Journal-Constitution via AP, File))

Why do Black Friday shoppers throw punches over bargains? A marketing expert explains

Colleen P. Kirk