If you've purchased clothing during the last month this can also be used in conjunction with any account credit you've accrued over January..
So for example, you might have £30 account credit (which you should by now have received in voucher code form from CDiscount.)
If you were to buy the Evisu jeans for £60, pay £30 cash and use £30 account credit. During February you'll receive 50% of that spend back, so ANOTHER £30 credit to spend on whatever you want!
Plus, you can use code "FREEDELIVERY" to get £2 knocked off your postage costs (making economy delivery free, or rapid delivery 99p)