A Lesson Learned at Lunch, Part 4

After finishing my sub, I headed to the shoe store for a pair of shoelaces.

I entered the store, which, by the way, was right next to the sub shop. I saw no one. But I found the display of laces and located the ones that would be the best fit.

No clerk emerged. So I went looking. I found her stocking shelves. I asked her to allow me to pay for my laces (it's been a while since laces cost 10 cents) and left the store.

Have you identified the common theme?