Spirit’s specialty is the supercheap ticket from a major American city to vacation spots like Jamaica, the Dominican Republic and Puerto Rico, and it’s ideal for people spontaneous enough to jump on last-minute sales, sometimes for tickets that cost as little as $9, one way.

But consider yourself warned: Spirit unabashedly contends that its only obligation to customers is getting them safely from Point A to Point B. Everything else is extra. And like its European inspiration, Ryanair, the company takes the word “nonrefundable” very literally. There is no excuse, plea or tap dance that will save you from the $110 change fee if you miss your plane.

Not surprisingly, a lot of people find this  there is no other word  outrageous. Given that Spirit flies about seven million people a year, just one-tenth of the traffic handled by a traditional airline like United, it has inspired an amazing amount of online venting, to the Department of Transportation and on Web sites like consumeraffairs.com.

Most of it is from Spirit fliers who were charged fees they say they didn’t see coming, or couldn’t get refunds they thought they deserved, or who had to buy new tickets on different airlines when Spirit flights were canceled. (Spirit typically will offer to put you on its next plane, but if that plane doesn’t arrive for another day, and you need to leave that night, the response occasionally translates as, “Your problem, not ours.”)

Image Ben Baldanza is chief of Spirit, which prides itself on minimal service and low costs. Employees help by vacuuming the office. Credit... Alex Quesada for The New York Times

Is this, as they say, any way to run an airline?

Yes it is, says Ben Baldanza, 47, Spirit’s chief executive. A short, genial guy with wire-rimmed glasses and a big smile, Mr. Baldanza has one of those naturally booming voices that suggests he’s giving a speech in a banquet hall, even when his audience is two feet away. One recent afternoon, he sat at a round table in his office here, in a generic-looking industrial park about 25 minutes northwest of Miami, and explained his rather pitiless approach to cost-cutting and complaining passengers  particularly those who he believes have nothing to complain about.