Had this in my inbox earlier today
How to claim your 50 free prints! From what I can gather it's for new customers only.
Upload your photos
Add 50 6"x4" or 6"x4.5" prints to your basket
You will automatically recieve 30 free prints when you join but to get your extra 20 free prints, (50 in total) you will need to enter the offer code NMPRINTS at the checkout
You have to pay the normal £1.50 postage fee and only works for new customers.