WebApiConfig
    config.Routes.MapHttpRoute(
                    name: "person",
                    routeTemplate: "person/{firstName}/{lastName}",
                    defaults: new { controller = "Person", action = "GetPerson" });

public HttpResponseMessage GetPerson(Person person)
            {
                // person always null here
                //DO STUFF!
            }

public class Person
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }