upselling
noun [ U ] uk/ʌpˈsel.ɪŋ/ us/ʌpˈsel.ɪŋ/
business specialized向上推销（试图说服顾客购买额外或者更昂贵的产品）
the act of trying to persuade a customer who is already buying something to buy more, or to buy something more expensive
The salesmen always look for opportunities for upselling. 推销员总是在找向上推销的机会。