Do sales encourage hoarding?

Well, not hoarding as when there are short supplies but this title sounded catchier. Whenever there are sales I tend to buy a lot more than I need at the time rationalizing that I will eventually get around to using whatever it is that is on sale: toilet paper, paper towels, soap, shampoo, etc. A consequence of all this is that I need to find room for all this stuff. So the question now is: Do sales (and Cotsco) cause us to want more room in our houses, or even catchier (and probably more inaccurate), do sales and Cotsco cause McMansions?