Especially when airline airplanes are also used for shipping. No need to even show up.
"With over 3,400 flights a day to Southwest destinations coast to coast, Southwest Airlines® Cargo has the flight you need, when you need it."
http://www.swacargo.com/swacargo/home.htm
"With over 3,400 flights a day to Southwest destinations coast to coast, Southwest Airlines® Cargo has the flight you need, when you need it." http://www.swacargo.com/swacargo/home.htm
http://www.delta.com/business_programs_services/delta_cargo/...