When you sign up as a member of Spirit Airline's "Free Spirit" frequent flyer club, you will be able to take advantage of their buy one, get one free promotion. Here is what you need to do:
1) Between now and December 24 at 11:59pm ET. you must register for the buy one, get one free promotion and book a qualifying roundtrip flight with Spirit for travel between January 5, 2009 and June 17, 2009.
2) You must include your "Free Spirit" number on the reservation when you place your order on spiritair.com
3) Around July 15, 2009, for those who qualified for the promotion, Spirit will send you an e-mail voucher in the amount of your purchased tickets price (less any taxes and fess), to the email that you registered your "Free Spirit" account with.
Other restrictions apply, please see Spiritair.com for full terms & conditions.