This already happens in Europe, the home of the ULCC. RyanAir and easyJet both compete with each other, and with the 'big cheese' former state-backed carriers, like Air France, Lufthansa, and British Airways. Both of them do fine, one with a slightly more 'low cost' product, the other with a touch more service and class, and a touch pricier too. Now there will be another option for low fares here in the US. The carriers that should feel threatened are Southwest, jetBlue, and the legacies - any carrier with higher costs that would see their passengers choose lower fares. Spirit is small potatoes, and so is Frontier. But now that both will likely be offering similar products, the threat to the competition just doubled. For Spirit, there's still enough passengers that will go for low fares to allow Frontier to get some of that pie too and not impact us too much.

Frontier has to clean up their balance sheet, get out from under a huge debt load, and restructure their entire company towards a new paradigm. They have a long way to go before they are a serious competitor in the ULCC area, but that's what Indigo is there for, to back them with the $ and the 'tough love' through the turbulent years to follow.

Frontier is likely bloated in many areas - they're going from a customer service airline with TV's in the seats to an airline that may have managers take out their own trash and no receptionist (), and they have to do all of it competing head to head against the world's largest airline (United) and the US's largest domestic carrier (Southwest). Not to mention the great situation that Republic and Bedford probably left them in. If there were rainbows and butterflies in the future, Bedford wouldn't be selling them.

The biggest threat to Spirit is Indigo has all of our inside info on our plans. They know our current weaknesses, all of growth plans, and how we deal with competition - Indigo had a hand in crafting these strategies. Now Indigo can try to build a better version of the same company, learning from the mistakes that Spirit made.

I'm not overly concerned about Spirit's future, but the future for Frontier - as a company - just got brighter. The situation for individual employees at the company may be a bit more mixed - Indigo (and Oaktree) left a wake of jilted former employees over their time at Spirit, and took their pilots into a strike. Indigo is now a leaner, and meaner, machine, and they have shown they are not afraid of rolling up their sleeves and getting dirty in an effort to achieve their goals.

The future will be interesting. Good luck to us all.