VIP2015MATSHOP
"To thank you for your support throughout the year we would like to offer your free shipping on your next purchase."
I've tried and confirmed code to be generic and not targeted.
Newsletter doesn't mention an end date.
Enter code at checkout page, under 'Discount Codes', free shipping option will appear under 'Estimate Shipping and Tax'.
Notable deal which has been posted a few times :
Dark Brown Prestige Heavy Duty Outdoor or Indoor Mat 45 x 75cm $14 delivered.
My family liked these a lot.
+1 for the dark brown variant as mentioned in OP's post.