If you are selling a commodity, you are nobody. Consumers will just switch to another “nobody” for a slight price difference. You have to keep promoting (or shouting?) to attract customers with no sustainability of such promotion in the long-run.
If you are selling a “me-too” brand, you are somebody. You could be a weak brand, but still your odds are better than selling a mere commodity. You may keep promoting (or yelling?) to attract customers, with little better sustainability than that of the commodity, except that consumers will switch to another me-too brand for a better bargain or when you stop promoting to them.
If you are selling a unique offer/solution that keeps customers loving you from their hearts, you are someone special – we call it Brand! You still need promotion to keep telling your customers that you are always beside them, rain or shine.