MIAMI — Earlier this week, New York-based JetBlue Airways held its annual investor day in New York City, covering a wide variety of topics related to the company’s business strategy and current financial results.

In particular, there was a heavy focus on JetBlue’s network of hubs and focus cities encompassing Boston, New York JFK, Orlando, Fort Lauderdale, San Juan, and increasingly the Los Angeles metropolitan area (primarily via a focus city at Long Beach but also with an increasing focus at LAX). JetBlue also spent a decent portion of the call highlighting the runaway success of the Mint business class cabin.

Mint is a margin machine on the existing routes

I apologize for the alliteration, but based on the figures JetBlue rolled out during the Investor Day, the Mint product has been performing spectacularly. In June 2014, shortly before the launch of Mint on JFK to Los Angeles and San Francisco, those routes had margins that were roughly 5 and 20% worse than JetBlue’s system average. Today they are 17 and 18% better respectively than JetBlue’s systemwide average.

Now, obviously, there is some noise in these figures as JetBlue loaded a high revenue product onto these routes even as the rest of the system was seeing revenue declines as a result of lower fuel prices. Still, it is clear that Mint has been nothing less than a massive win for JetBlue.

However, it was always likely that JetBlue would succeed in the New York – California markets. There was already a history of passengers paying for pure international business class products in those markets, and JetBlue was significantly undercutting the pricing of the existing players.

The less clear avenue of expansion was Boston, where Mint would actually be priced above most of the domestic first class products in the market(s) and where American had withdrawn premium transcontinental service that it had used to serve with its Boeing 767-200ERs. But even in Boston, the launch of Mint on Boston-San Francisco has seen the route improve from roughly system average in terms of margin to 5-6 points better.

JetBlue expects to see a similar performance from the launch of Mint on Boston – Los Angeles.

JetBlue’s Mint expansion has some risk

But it is fair to say that JetBlue is planning Mint growth for 2017 and beyond on the basis of one real data point of success (New York to Los Angeles and San Francisco don’t really count) in Boston – San Francisco and expanding into markets that lack a history of paying for this kind of domestic premium cabin service. Fort Lauderdale, while a JetBlue hub, isn’t really a premium destination as that traffic prefers Miami in the South Florida metropolis. San Diego, to be served from New York JFK, is at least wealthy enough to fill the premium cabin on leisure traffic.

And its even more unclear if markets like Boston to Seattle/San Diego or New York to Las Vegas (vacationer traffic may make this one work) or Seattle will find success. While Mint has been excellent so far, JetBlue has made big plans on the basis of not a ton of validation.

Where might JetBlue expand from Boston

The section of the presentation focused on the Boston hub created another opportunity for JetBlue’s team to puff out its chest at runaway success. Namely, that Boston has slowly but steadily, over an 8 year period beginning in 2008 pulled away to outperform JetBlue’s network in both margin and absolute profits. And JetBlue believes that the Boston market it still underserved, pointing to a chart that shows its market position in Boston as weaker than that of other #1 carriers in similarly sized hubs. JetBlue is up to 61 nonstop markets, and at the end of 2017 will be in 39 of the 50 largest domestic and international destinations from Boston based on origin and destination traffic.

The missing markets at the moment are St Louis, Milwaukee, Columbus, Indianapolis, and Kansas City domestically (all dominated by Southwest) as well as Minneapolis St. Paul (going into two Delta hubs in 2017 might have prodded Delta into all out war in Boston so perhaps its for the best if JetBlue waits on that one a bit).

Internationally, the markets included Toronto, Reykjavik, Dublin, London Heathrow, and Paris Charles de Gaulle. All of those domestic markets will probably be eventually added on the strength of JetBlue’s business traffic in Boston, but the more interesting question is indeed around the international routes.

I’ve long been a proponent of JetBlue using Boston as a trans-Atlantic gateway – it’s a market where they’re uniquely positioned to capture the kind of high-yielding business travel that’s critical to allowing long haul routes to succeed. Boston is also a base for the Mint A321s so the product rotations are there to enable this growth, and really it’s just a matter of when. The A321neo will have trans-Atlantic range, particularly for Ireland, London, and even Paris from day one.

The rest of continental Europe will probably require the A321LR, but Boston’s location is great for connecting passengers to Europe, and it’s not hard to envision them building up to 10-12 European destinations. The one caveat here is the airport infrastructure, as this process would be made much better if JetBlue and Massport could add immigration in Terminal C (the trek from Terminal C to E isn’t fun).

Growth in Fort Lauderdale as well

Not to be left out, JetBlue sees growth opportunities in Fort Lauderdale as well, where it has a RASM premium and higher local traffic share than rivals Southwest and Spirit. Fort Lauderdale’s margins still lag the systemwide average, and while JetBlue tried to overlay the Fort Lauderdale margins over time on the graph of the same thing in Boston, the difference is that the Boston chart started in the middle of a recession (accounting for the margin decline) while Fort Lauderdale expansion was launched amidst an economic recovery. It’s clear that (relatively speaking) Fort Lauderdale is a bit of a bloodbath.

At the same time, JetBlue has big plans for growth from Fort Lauderdale, where it serves just 29 of the 50 biggest domestic markets. There are obvious adds like Denver, Dallas, Houston, Atlanta, and Seattle on the domestic side, but the international side of the equation is a great mirror image for Boston – Fort Lauderdale should be JetBlue’s gateway to South America. It already serves Bogota and Lima, and while Caracas is a stay away, Panama City, Santiago, Buenos Aires, Sao Paulo, and Rio are all realistic adds.

London Heathrow and Madrid are also amongst the largest markets, but hard to justify in terms of investment as they would require widebodies for service from South Florida.