Flying twice is nice on JetBlue. Book a flight on jetblue.com by August 6, 2018, and you'll receive a 20% off promo code valid for travel on a future flight.

Fly by the End of August and Receive a Promo Code for Fall Travel

One-ways and roundtrip fares qualify, however, one flight on the reservation needs to be completed before midnight on August 31, 2018. One promo code will be issued per booking, with up to a maximum of seven promo codes total, so if you are a frequent flier or are planning a few last minute trips on JetBlue, stack up on those codes. 

Once you receive your promo code by email, the 20% off can be applied to fall flights departing September 25 through October 31. Codes can be used for travel on Monday through Thursdays and Saturday departures. Travel is blacked out October 6 through 8^th.

To me, it seems like a lot of hoops to jump through to qualify. But if you find yourself planning a flight on JetBlue in August, you might as well take them up on the 20% off code for future trips. Unfortunately, the promo code won't be sent out to travelers who have made previous bookings.

To find out more, you can visit the JetBlue fine print page here.