When we shop we aren't just shopping for physical goods. We have an expectation of the experience of shopping. Even at the supermarket we expect not to queue for hours.
As the luxury of a purchase increases, so does our expectation until the experience is as important as the purchase itself. After all, this is an investment of time as well as money and whether it's a piece of furniture, diamonds or an exquisite suit, this is something that will reflect who we are. It is an emotional transaction.
This certainly puts pressure on the purveyors of luxury goods! Those who are supremely successful, are those whose staff understand that they are most certainly not chasing a sale, they are building a relationship with their customer.
Sales personnel must be up to the task. Of course, they must have beautiful manners and be impeccably turned out. But they must also have the emotional intelligence to be able to vary their service according to the customer. It's not easy. But when we are investing in something of value, we want retailers to put as much effort and care into how they treat us as they have into the creation of their product.