5. What are some ways to implement your recommendation? What do two satellites, one named "Rock" and the other named "Roll," in orbit 22,500 miles above the equator have to do with one of the fastest-growing new services in America today? Those satellites, costing $200 million apiece, broadcast radio signals to receivers owned by subscribers of XM Satellite Radio's service. XM Radio is a company that provides over 150 different satellite radio stations to over 6.5 million customers throughout the United States at a cost of $12.95 per month. Similar to satellite TV, satellite radio is a relatively new service that beams radio signals from its broadcast center to the satellites, then to subscribers. In addition to the monthly subscription fee, XM subscribers pay anywhere from $49 to hundreds of dollars for a receiver they can use in a car, truck, boat, or boom box. The United States has approximately 200 million cars and light trucks, 4 million boats, 3 million heavy trucks, and 100 million households-obviously a huge potential market for satellite radio.