Dogs fall ill after eating shop's chocolate freebie
A Sainsbury's spokesperson said
"We know chocolate is unsafe for pets to eat and that's why we had measures in place to safeguard against pet owners receiving this promotion," they added.
Hmmm. This is 1+1=3 in their DataWarehouse IMHO. How do they know whether Sainsburys Customers are pet owners or not?
My guess is that they used Nectar Card (their loyalty card) history to work out if you've buying dog food with it. If you haven't then they assume you don't have a dog.