Ultra Low-cost airline expansion is in full flow in Atlanta. Who will be the winners and losers?

Atlanta Hartsfield Jackson international Airport has become a hotbed of ULCC activity in 2015 as both Frontier Airlines and Spirit have made a push from the airport. With their entry, roughly six of Atlanta's top 10 markets have received an injection of ULCC competition, challenging the airport's largest airline Delta and second largest Southwest.

Atlanta seems like a reasonable target for ULCCs given its domination by Delta, which controls the vast majority of the airport's ASMs and seats. It is too early to make any real determination of the ULCC impact in the market, but Atlanta is an interesting testbed given that many routes that the low-cost airlines have entered were previously duopolies controlled by Delta and Southwest.

The ULCC's competitors in Atlanta have increased seats in many of the markets where the new airlines have launched service, due in part to the summer high season. However, the large network airlines are also poised to compete feverishly, and will not relinquish any of their dominance easily.