To me, "Slept on" doesn't mean you could get them sometime during the first 4 hours a store was open. Slept on means they're sitting around, they go through the product cycle, they go on sale, etc...people choose to leave them on the shelf for a cycle, rather than get lucky that they are on the shelf for a day. If a shoe is at a local store and would still stay sitting there if the whole country had access to it, then maybe that's slept on somewhat.
What happens at your Sports Zone happens at our Hibbet's Sports sometimes. People have caught on there now though it looks like.