兴隆 (xīnglóng) describes a business, shop, or industry that is thriving and doing well — it's the go-to word for a prosperous store or company. Compared to 繁荣 (fánróng), which is broader and used for economies, cities, or cultures, 兴隆 is more specific to commercial success. It's less colloquial than 红火 (hónghuo) and more concrete than 兴旺 (xīngwàng), which can also apply to families or causes.