Cannot check in for an economy flight where the outbound and return flights occur on the same day. Economy at Frontier means you don't get a seat until checkin. This problem with their checkin system means you cannot check in for the return flight until after the outbound flight. SO, while everyone else is reserving their seat for the return flight, you are stuck simply because you wanted to travel on just one day. Their web support person called this request "absurd" and promptely "accidentally" dropped my call. read full review »