What Soda Does Marty McFly Drink In Back To The Future?

Throughout the Sci-Fi comedy Back to the Future film series, Pepsi Cola makes repeated appearances. Why Pepsi and not, say, Coca-Cola? Did Pepsi pay more for product placement? Did Coke scoff at the idea of even paying for product placement in the first place? via Pocket http://ift.tt/1mjj9HV