I have flown Spirit Airlines several years ago. They are no frills but cheap! They are offering 1,000 miles for free through the billion miles jackpot.
You can enter here to receive your free 1,000 miles: http://marketing.spirit.com/jackpot/
So what does 1,000 miles get you on Spirit? Generally a magazine subscription. Spirit miles are pretty much only good for 90 days unless you add more activity to them. Points said they would post in 14 days.