The boxy, brick-fronted shop in the town square of Scottsville, Ky. (population: 4,500), is one of the oldest stores in the Dollar General chain—and it looks its age. The aisles are cluttered; the ceilings are low; the lights are dim. There are rows of plastic storage containers, towers of paper towels, and fridges full of frozen pizzas—the kind of seemingly random, dirt-cheap bric-a-brac that fits the drab dollar-store stereotype.
But not far past the entrance, shoppers can spot something incongruous: a sleek cooler full of Starbucks drinks, topped by the coffee chain’s smiley mermaid logo. There, a shopper can grab a Doubleshot espresso for $2 or get two cans of frappuccino for $5. They’re the sort of modest extravagances associated more with…….