Wow, this is super, and no word on how long it's valid for, but use promo code 50%off in the promo code box at Allegiantair.com and you will get 50% off your flight. Just be sure avoid extra fees and "upsells"; buy your ticket at the airport and not online to avoid the "convenience" fee; don't check bags. We found seats on the Allentown/Mrytle Beach route for 1/2 off, but the code doesn't work on all routes or dates.
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