Claudine Adamo

The key to Costco’s success is its ability to offer customers both low prices on bulk items (think 30-roll toilet paper packs) and treasure-hunt discoveries (like a 72-pound wheel of Parmigiano-Reggiano). The executive most responsible for striking that balance is Claudine Adamo. As COO in charge of merchandising, Adamo has outsize influence on what 152 million Americans buy: The 33-year Costco veteran oversees teams of buyers who determine what products are on its shelves, which ones are bought from vendors, and which are made under its $60-billion-a-year Kirkland store brand.