I’ve read in this book that shopping stores have a strategy – they tend to put items that can be compared with other shopping stores at a lower price. And items that can’t be easily compared at higher prices.
For example, milk, eggs, tomatoes – these tend to be generic products, and have lower profit margins (have smaller prices).
But a specific olive oil, or wine bottle that is not so common – this is a specific product, and they tend to put a higher markup price.
Nice book, not only for this fragment!
