Are you sure about that? Operated by QR, yes. But marketed (in this context) just means that your "flight coupon" (referring back to the old days of paper tickets) for the flight has a QR flight number. For example, my tickets are all issued by AA, on 001 stock, yet I achieved QRPC PLT in the past 12 months. I have never purchased a ticket from QR, and have never had a ticket number that begins with 157.