I know Kitbag has been doing promotions from time to time but it's rare that they do 15% discount and free delivery at the same time.
Bear in mind that you have to order more than 60 pound to get the free delivery.
I've been their customers for some years. Most of the time, the parcels would arrive in 5-7 working days for the free delivery even though Kitbag claimed that 3-10 working days.
looks like an OK deal but difficult to find my size in their footy boots, a lot sold out.