Found this last night when checking the opening hours for the Swindon outlet. Simply enter your details & email address, they send you an email which you print out and take it to which ever outlet you're going to and swap it for a 10% discount card for that day. The card isn't accepted in all shops but considering its free seems a good deal (we saved £4 in clarks & £1 in Bench).
The email we received is valid until November and I cant see why you couldn't just use a different email address and apply again (or just re-print the email as they didn't check it today)
Available for Ashford, Bridgend, Cheshire Oaks, East Midlands, Livingston, Swindon or York outlets.