According to Cahners In-stat Group, the number of worldwide wireless phone subscribers will soon reach the 1 billion mark . In the United States alone, the number of wireless subscribers is projected to grow by almost 17 million subscribers per year for the next 5 years. Contributing to the extensive growth are lower prices , large geographic coverage , prepaid services, and Internet enabled phones. While the actual cost of a basic wireless phone is about $75, most wireless carriers offer their customers a "free phone" with a one year wireless agreement. Is this pricing strategy rational? Explain.