Adopted from the following great insight shared by Simon Sinek from his book Start With Why

United had TED ,Delta launched SONG but both failed , WHY?

In order to compete with the iconic brand SouthWest Airlines in the economy airline segment , United launced TED while Delta Airlines launched SONG.

Both these brands failed.It is not because of WHAT they did it is because noone was convinced WHY the brands existed in the first place.

SouthWest on the other because of their very clear and crisp messaging and communication of their WHY was able to have loyal customers unlike Delta and United.

Without a clear sense of WHY in their messaging the customers had to judge TED and SONG solely on price or convenience.

This the major reason both the brands failed.