Costco Wholesale's Sales Are Increasing Modestly, But 1 Part of the Business Is Gaining Much Faster

Costco's Q3 2025 results show modest overall sales growth (under 6% same-store), but e-commerce net sales grew nearly 15%, and membership income rose over 10% due to price increases. The company leverages its growing digital business, including partnerships like Affirm and its Costco Next marketplace, to generate advertising revenue and maintain low prices for members, driving strong membership retention (close to 93%). While retail sales growth is moderate, the focus on membership and digital initiatives supports Costco's long-term profitability.

Analysis

Costco Wholesale (COST) demonstrated significant operational scale in its fiscal Q3 2025, with its 905 locations achieving nearly $62 billion in net sales, averaging approximately $68 million per store for the quarter. However, overall growth presents a mixed picture: same-store sales increased by less than 6%, indicating a mature phase for its core retail operations. More dynamic growth is evident in its digital segment, where e-commerce net sales surged by nearly 15% in Q3 and over 16% through the first three quarters of fiscal 2025. This digital expansion is strategically important, supported by partnerships like Affirm and the rapidly scaling Costco Next marketplace, whose Q3 sales exceeded its total for fiscal 2022. Costco leverages its unique member data to generate advertising revenue, which it reinvests to lower product prices, thereby reinforcing its value proposition and high member retention, which stood near 93% in Q3. While paid membership growth was 7%, crucial membership income rose over 10% year-over-year in Q3, primarily due to price increases, significantly impacting profitability as these fees are a core component of earnings. The company's strategy emphasizes leveraging digital growth and advertising revenue to maintain low prices, which in turn supports its highly successful membership-based business model rather than relying solely on retail sales margin.

Key Decisions for Investors

• Investors should prioritize monitoring Costco's e-commerce growth rates and membership income trends, as these are currently the primary drivers of upside, given the modest growth in same-store physical retail sales.
• Consider the resilience of Costco's business model, underscored by high membership retention and the strategic use of advertising revenue to maintain price leadership, which supports long-term customer loyalty and predictable revenue streams.
• Evaluate whether Costco's steady, membership-driven profit growth aligns with investment objectives, especially in light of its mature retail segment, and weigh this against the article's subtle suggestion that other stocks might offer higher near-term growth potential.