I was about to book an extra Orlando trip for this summer when this deal came out, but... Frontier seems to be doing some creative math with regards to airfare, taxes and "carrier imposed fees" for this deal. For example 2 adults and 2 children (10 & 7 so it meets their criteria for the offer):
Regular price listed $69 per person each way ($130.24 airfare and $142.96 taxes and fees total each way) for a total of $546.40.
Discount Den price (not including cost of membership) listed $59 each way for the adults and kids fly free. ($95.60 airfare and $140.36 taxes and fees total each way) for a total of $471.92.
So a round-trip savings of $74.48 using 2 kids fly free tickets each direction.
I can't for the life of me figure out the math behind it. I understand taxes for the total value of the free ticket and such. Even just looking at the airfare portion the $130.24 each way for 4 tickets is $32.56 per ticket. On the free deal the $95.60 airfare each way for 2 tickets is $47.8 per ticket. And that is on the Discount Den fare that is listed as $10 less than the regular fare.