For example, the company runs the risk of cannibalizing existing sales by aggressively opening new stores. Costco currently operates 474 warehouses in the United States, and the company plans to open as many as 20 new locations in the U.S. this year. The concern is that these newer locations could pull members away from Costco's existing warehouses thereby hurting same-store sales and in-store traffic at its current store base. That said Costco still has a smaller footprint than Wal-Mart's rival wholesale chain Sam's Club, which counts 647 locations in the United States today.