Some thoughts (and some of them agree with others''):
-- STL is NOT a peach just waiting to be plucked. There are too many hubs already in this country, and STL''s potential as one is burdened by a large LUV presence.
-- U cannot effectively compete with LUV in the long term. Someone else posted the CASM numbers. There is still a large gap in costs.
-- LUV naturally often does not have the lowest fare. That is how one makes money in this business -- by not having the lowest fare. LUV has some really low fares as loss leaders, but LUV limits their availability and they do their job and get people to fly the airline. But LUV almost always has the lowest BUSINESS FARES, and that is the key. Where the cartel airlines charge $2,000, LUV might charge $600. Also, LUV has the reputation of having the lowest fare. Many people will check LUV, and only LUV, when looking for a plane ticket because they trust that they will get a good price.