Costco fever, this time at my local Stew Leonard's. It's not clear to me that the price on these socks and snacks (of course, socks and snacks, right next to each other!) is particularly good. And there's certainly no reason to stack them up in such a huge pile.
Except there is. The reason is that the stack is lying to you, telling you a story about volume and value and urgency. This must be a great deal! They bought so many! They've got to clear them out! (and then, paradoxically, "They might run out soon!")
The punchline: this works because people like us like it. It makes us feel good to buy what feels like a bargain, even if it's not.