A stadium is a building in which lots of people may watch an event. They are often used for football and athletics. Some stadiums are paid to add a company name to the name of their stadium. For example, "Comerica" Park in Detroit, Michigan, or the ALLTEL Stadium in Jacksonville, Florida. When people do this the company has the "naming rights" to the stadium. The name of a stadium can change when another company buys the naming rights to that stadium.