Here's my idea:

I't always bothered me that FF rewards are based on segments or distance tavelled instead of amount of revenue that you created for the airline. Airlines recently started to give extra miles for flying first class, but that still does not justify thoes flying Y (full fare). I think I know why airlines don't give rewards based on how much was spent to buy the ticket and that is bec. Airlines need bussiness travellers for them to survive and if they start rewarding them based on how much their companies payed for their tickets they'd be in trouble. (BTW I recently noticed that AA has started some sort of program for companies to collect points for the tickets they buy for their emploeeys without taking away the regular miles the passenger receives for flying, I wonder how that program is doing)

So here goes my idea: considering the fact that JetBlue is a lowfare airline, their bussiness plan does not involve getting more money out of bussiness travelers than out of leisure travellers, and the difference between highest payed fare to lowest on any one of their flights is not all that much then I would set up a FF program that rewards travellers based on the amount of revenue the traveller produced for JetBlue and that would be the money they payed for their fare (before taxes of course bec. that dosen't go to the airline)
I think all travellers would appreciate such a program give the airline revenue get free tickets.