Costco operates a global chain of membership-based warehouse clubs that sell a curated selection of branded and private-label merchandise at low prices. The company uses a no-frills warehouse format with fewer than 4,000 SKUs per location, selling items in bulk quantities to drive high sales volume and rapid inventory turnover. Alongside national brands, Costco offers its proprietary Kirkland Signature private-label line and operates ancillary services, including gas stations, pharmacies, food courts, and optical centers. Costco generates revenue through merchandise sales and recurring annual membership fees across basic and executive tiers. While merchandise sells at low gross margins, membership fees provide high-margin cash flow and fund low product pricing, which reinforces member loyalty and shopping frequency. In addition to physical warehouses across the U.S., Canada, and international markets, Costco sells goods through e-commerce platforms and delivery partnerships. The company pursues growth by opening new warehouses globally and expanding its executive membership base.