Got this in an email - I think it is a single use code, so as soon as it has been used by someone, it's done. Says it is to 'try' Sainsbury's but I've used them before and they sent it to me.
PLEASE DON'T COMPLAIN THAT IT ISN'T WORKING - IT WON'T, AFTER THE FIRST PERSON HAS USED IT!
"Simply place an order for delivery on or before Sunday
23 November, spend over £50 and enter your evoucher number when you checkout"
Hope it helps someone.