I think that marketing pets at Xmas is about as bogus as offering cats at Halloween. People are more stressed, busy, and likely drinking more than at any other time of the year.
Many people are overloaded with stuff, stuff, and more stuff under the Xmas tree. Imagine the patience and understanding that some of those folks will have when Fido tears into all that new junk, or Fluffy topples the tree to get at her catnip!
The kids will be busy playing with their new toys, including the Nintendo "virtual dog" that the SPCA endorses as a learning tool.
The number one reason for getting a pet at Xmas will be as a "gift." If not, then why not get the animal at another time of year?
As to home checks, we know that in most or at least in many cases, the SPCA does not do home checks.
Cats and dogs are not one more commodity to add to the house at Xmas.