The luxury goods market for the ultra rich encompasses jewelry, cars, clothes, tableware, ornaments and much more. If luxury hotels, travel and other services are included alongside retail sales, this sector amounted to $1 trillion dollars in 2015. As such, there is a vast grey market for goods that mimic the priciest brands but sell to people who are less well off. Ian Phau and Min Teah of Curtin Business School, at Curtin University in Perth, Western Australia, explain how, "brand familiarity is postulated to be a mediator between perception of luxury and product evaluation.