Case in point - about 5 years ago we paid for my parents to stay at POR for 3 nights with us. Mom and Dad are in their sixties, no kids around, and on a very limited income - dad is half-retired and mom never worked. I made the reservation for them, and paid with my credit card.
About a month before we arrived, mom and dad get a postcard offering them an upgrade to SSR if they can change their travel dates.

Now, we are traveling as a family - I paid for the reservation - CRO has no social security card or credit card for my parents, just an address that I gave them.
Since then, my dad has gotten a pin code offer once or twice every single year. Seriously. He's got no intention of ever traveling to Disney unless we pay for it again

.
In the meantime - here my husband and I are

: dual income, two young kids, mid-thirties, homeowners, good credit. Just the kind of people most likely to buy DVC (which, of course, we did). We never got a PIN offer.