Sale fares under the promotion start at $19.90 one-way for members of Spirit's $9 Fare Club, an annual membership program boasting exclusive deals. A limited number of dates and routes are available under the promotion. Act fast, though, if you're interested — the sale ends tonight at midnight. (Click here for the full list of fares and destinations.)
Spirit's previous kitschy ad poked fun at Republican presidential candidate Mitt Romney's "binders full of women" remark at a debate.
(Read More: Spirit Airlines Offers 'Binders' of Airfare Sales)
Before that, Spirit targeted American Airlines' woes with loose seats on its Boeing 757 fleet. They ran a sale offering 7.57 percent off fares promoting it as, "We let fares loose, not seats!"
More Loose American Airlines Seats Found
Misty Pinson, Spirit's director of corporate communication told CNBC.com in an email several months ago that these edgy promotions are not created by outside marketing firms. The process "tends to be a group effort … albeit a small group," she said.
Clever or crossing a line, you be the judge.