Instructions:Just found this on Bounty's JUMP magazine:
Enter the code:M4-JU-MP-72 Exp. 31st Aug 2009
1. Free delivery is valid on grocery orders of £50 or more placed on www.asda.com and delivered on or before 31st August 2009.
2. Only one offer can be claimed per household.
3. Offer only valid for customers who registered on the groceries site after 30th June 2009. Asda reserves the right to withdraw the offer at any time.
4. Asda Home Shopping is available in selected areas only.
5. Please see the help section on the grocery website for full terms and conditions.