Frontier Airlines just started 1 day promotion for flights from/to several US cities. Tickets from 19 USD one way and 38 USD round trip!
Reservations till 23:59 PM Eastern US time.
21 April – 13 May 2015.
from Atlanta to 8 Cities.
From Cleveland to 3 Cities.
From Denver to 16 Cities.
From Washington DC to 4 Cities and much more.
How to book: