I assume that you have received "great coupons" at the checkout of your local grocery store, or perhaps CVS. I believe the intent is to target coupons to each customer based on their purchase. Get you hooked on a product that correlates. Easy marketing.
A good example is:
You buy a bottle of wine.
They reason/deduce/assume that you are drink wine.
The coupon is for a new, different wine company.
Another good example is:
I bought Tostitos Chips. (Can't eat potato chips because of potassium. I miss potato chips!)
They figured that I like me some tortilla chips. (And very right they are!)
The coupon is for Queso Dip. Good call.
In reality, though, I have experienced some pretty strange purchase-to-coupon transactions.
I bought five pounds of post-Halloween candy.
They reason that I like candy and sugar.
They should have give me a coupon for more candy, perhaps a different brand.
The coupon is for toothpaste!
I sure didn't like the implication there!
What sort of fun non-corresponding purchase-to-coupon's have you received?