My closest TSC carries stuff that the local hardware and box stores don't, like tractor mufflers, electric fence chargers, real t-posts and hog panels. Their prices are better than most on stuff like chicken feed, but I kept going back looking for oyster shell and I could never find it. Next time in, I cornered a manager and he was all "the order comes in on wednesday and is gone in an hour." And I asked him if he ever considered, you know, ordering more?
Next time in after that, it was on the shelf.
I like their bulk bolts. They never have any 4-1/2" cut off disks in stock. It's all very hit and miss, but most of the time I am able to check online to see if they have what I need in stock before I make the trip.
I used to work at a department store fresh out of college. Store manage told me that the markup on most stuff is somewhere around 5-15%, and is very price competitive, except clothes, where the markup is 90%. They were still making good money at half off.
So that's why any store will focus on the clothes, that's where they make the most. Personally, I think the clothes prices at TSC aren't great either, and never have what I want anyway. But I am also sure they sell far more shirts than 9n mufflers.
I know the kids at my store know what a tractor looks like, because they can see the deere dealer on the other side of the parking lot...