Nobody knew about it, so the loss of traffic more than made up for the decreased costs there. Kind of like how Allegiant tried MCO instead of Sanford...except Allegiant moved back to Sanford when the experiment was all said and done.

Speaking of which, Allegiant is the big player at PIE. It's the Phoenix-Mesa to Tampa, so to speak. Or the Sanford to MCO. Frontier was kind of our of place there since it isn't a ULCC with a distinct aversion to planes built during this millennium

FSD/BIL, maybe. FAR, doubt it until F9 decides to serve DEN at that airport. Serving MCO/TPA (or, rather, PIE/SFB) without allowing connections to the rest of the US through a more centrally located airport is Allegiant's business model (and Airtran's to an extent, though that will change with the WN purchase), not Frontier's.

Examining the situation more closely, F9 isn't in FAR right now. In BIL they might be able to make a go of it since G4 only goes west of the Mississippi from there.

FSD would be...interesting. F9 has one evening flight into and out of there, on an E90. No connections are possible to TPA or MCO. Allegiant hits these routes with an M80 of some sort, twice a week during peak season, so 260-332 seats per week available. Fares very, but lowest I could find was $130 or so OW. The big question here is whether F9 can take an E90, throw it into FSD 3x a week (297 seats) and get the plane reasonably full. Or, for that matter, 1x a week on Saturdays, keeping in mind that Delta offers round-trips for $200 OW with a reasonable connection time.