More precisely, you’d use お待ちください if you were addressing a social superior. So yes, a shopkeeper addressing a customer, an underling at a company addressing an… overling, a commoner addressing a noble. (You’d only use it in @TheCodingFox’s hypothetical if you were the shopkeeper. It’s not for customer-to-customer interactions.)
It’s a type of formal language called 敬語, and… it can get complicated, even to the extent that native speakers can struggle with it. You should certainly be aware that it exists, but I wouldn’t focus on it too much at this stage in your learning (though other 敬語 phrases you’ve probably already encountered include shopkeepers saying いらっしゃいませ when you enter a shop, the いただきます before eating, or the お休みなさい to someone going to sleep).