Costco operates membership warehouse clubs in 24 US states, the UK, Mexico, Canada, and Asia. It has over 16 million member households that contribute $400 million in annual fees. Costco aims for high volume and large scale operations with limited product assortments of around 4000 SKUs. This allows for efficient shelf space, fast inventory turns, and low costs. Costco looks for opportunities to expand domestically through new warehouses and membership models. It also looks overseas at locations like the UK, Mexico, and Asia for international growth. Managing the balance between membership services, marketing, pricing, and the core warehouse business model presents dilemmas around maintaining the customer value proposition.