Instructions:**Next time you book - get £10 off per passenger (£5 off each way)**
When you fly with them, they give you a card with a code on. I have entered four different codes now and they were all for £10 off a return flight and the promotional code was always the same. So there not unique to me. It's not a massive saving but it's better than nothing!
There should be the option to enter the code when you go through the online booking system.