7-Eleven, Inc., operates more than 20,000 convenience stores worldwide. Edward Moneypenny, 7-Eleven's chief financial officer, was asked to name the biggest risk the company faced. He replied, "I would say that the biggest risk that 7-Eleven faces, like all retailers, is competition ... because that is something that you've got to be aware of in this business." In what sense is competition a "risk" to a business? Why would a company in the retail business need to be particularly aware of competition?