Not unlike a limousine, taxi or courier service, the largest challenge to overcome in starting an airport shuttle service is to acquire an operator's license. An operator's license can be difficult to get through local government channels in most areas of the country, and very expensive if you plan to purchase one from an existing shuttle service. However, it's certainly not impossible to obtain an operator's license for a shuttle service, and it can be well worth the effort. An airport shuttle service can be a very profitable business to own and operate. Marketing a shuttle service is best accomplished by building alliances and partnerships with companies and local businesses that can supply you with customers, such as hotels, tour operators, travel agents, and large corporations.