flagship product; leading product; hallmark product
Refers to a company's most representative or best-known product, often used in marketing and business contexts.
This smartphone is our company's flagship product.
Sales of the hallmark product support the overall profit.
看板商品 is a shop's signature flagship product known for quality or popularity, while 目玉商品 (in its non-discount sense) is simply the item prominently displayed to catch attention.
Compound of 看板 (kanban, 'signboard' or 'symbol') and 商品 (shōhin, 'product'), literally 'signboard product', reflecting its role as the face of a business.