I've just received an email from jet2.com with an Offer of 10% off all return flights. You need to enter the following voucher code: SALE10

There are various terms and conditions as ever with these sort of offers:

Terms and Conditions - 10% Off
On air Tues 20th Mar 2012 – 2nd April 2012

Must be aged 18 or over to place a booking

One discount per booking

Promotional code (SALE10) must be added at the time of booking

Cannot be used in conjunction with any other discount

Offer valid on all flights booked from 0830 on Tuesday 20th March 2012 until 2359 Monday 2nd April 2012 inclusive

Offer valid until such time Jet2.com withdraws the promotional offer

Jet2.com reserves the right to amend or remove this promotion at any time prior to customer booking

Offer valid for return travel between 20th March 2012 to 15th April 2013 inclusive

10% discount will be applied to the total of any flights (including tax, but excluding booking fees and credit card charges) and retail products purchased at time of booking (excluding purchase of any travel insurance or car hire via Jet2.com’s website).

Applicable to new bookings only

Not applicable on any New York flights

Not available on one way flights

Offer only available when booked online at www.Jet2.com

Offer excludes group bookings

If flight dates or any passenger names are changed by customer following the original booking, the discount will no longer apply

All other terms and conditions as per the Jet2.com website apply