Analysis: Costco vs Sam's Club — Two Membership Models, Two Very Different Business Strategies

The most consequential difference between <a href="/posts/2026-02-28/cost-analysis-costcos-membership-fortress-at-449-billion-q2-earnings-preview-holds-the-key-to-the-next-move">Costco stock analysis</a> and Sam's Club lies in how each company uses its membership fee. Costco treats membership revenue as the core profit center of the entire business. In its most recent fiscal year, Costco generated approximately $280 billion in total revenue across four quarters (Q2 FY2025 through Q1 FY2026), but operated with a gross margin of just 13.1% — deliberately keeping product markups low to drive membership renewals. The company's operating margin of 3.7% and net margin of 3.0% reflect a business that prioritizes volume and loyalty over per-item profitability.

Sam's Club takes a different approach. As a division of Walmart, it benefits from the parent company's 24.7% gross margin structure and uses the membership fee primarily as a traffic qualifier — ensuring that only committed shoppers enter the warehouse, which improves per-visit spending and reduces shrinkage. Sam's Club membership revenue is meaningful but represents a smaller share of Walmart's overall profit mix.

Costco's membership renewal rate consistently exceeds 90% in the US and Canada, creating a predictable revenue stream that effectively subsidizes below-market pricing on everything from rotisserie chickens to Kirkland Signature vodka. This flywheel — low prices drive renewals, renewals fund lower prices — is the defining characteristic of Costco's competitive moat.

The raw revenue comparison reveals the enormous scale difference between these organizations. Walmart generated $713 billion in total revenue over its last four reported quarters (Q1–Q4 FY2026), with its most recent quarter alone producing $190.7 billion in sales. Sam's Club contributes roughly $86 billion annually to that total — making it a significant business in its own right, but still less than a third of Costco's standalone $280 billion revenue run rate.

Costco's quarterly revenue progression tells a growth story: $63.7 billion (Q2 FY2025), $63.2 billion (Q3), $86.2 billion (Q4), and $67.3 billion (Q1 FY2026). The Q4 spike reflects Costco's fiscal year-end alignment with the back-to-school and holiday shopping seasons. Year-over-year same-store sales growth has consistently outpaced Sam's Club in recent quarters, driven by both higher traffic and larger average basket sizes.

Walmart's competitive advantage lies in its omnichannel reach. While Costco operates approximately 600 US warehouses, Walmart has over 4,700 US stores plus Sam's Club's approximately 600 locations. This physical footprint, combined with Walmart's $100+ billion e-commerce operation, gives Sam's Club access to fulfillment infrastructure, advertising technology, and supplier relationships that Costco must build independently.

Despite Costco's intentionally thin margins, its capital efficiency metrics reveal a remarkably productive business. Costco's return on equity reached 8.9% in Q4 FY2025 and its return on invested capital (ROIC) was 6.2% — impressive for a company that deliberately suppresses profitability to benefit members. The company's debt-to-equity ratio of just 0.27 reflects a conservative balance sheet with minimal leverage.

Walmart's ROE of 4.3% in Q4 FY2026 trails Costco despite higher gross margins, partly because Walmart carries significantly more debt (debt-to-equity of 0.81) and operates with greater capital intensity across its diverse retail formats. Walmart's current ratio of 0.79 indicates it routinely operates with negative working capital — a common practice among large retailers with strong supplier payment terms, but one that requires precise inventory management.

Costco's current ratio of 1.04 and free cash flow per share of $7.12 (Q1 FY2026) demonstrate a more conservative approach. The company's cash conversion cycle of less than one day — meaning Costco sells inventory and collects payment before it has to pay suppliers — is among the best in retail. Walmart's cash conversion cycle of 2.6 days is also excellent but slightly less efficient.

From an investor perspective, both stocks trade at premium valuations: Costco at 54x trailing earnings and Walmart at 47x. These multiples reflect the market's confidence in both models' durability, but Costco's higher premium suggests Wall Street assigns greater value to the pure membership-driven approach.

Private label brands represent a critical battleground in the warehouse club wars. Costco's Kirkland Signature is arguably the most successful private label brand in retail history, generating an estimated $75+ billion in annual sales across categories from olive oil to golf balls. Kirkland products are priced 20-40% below national brands while maintaining comparable or superior quality — a strategy that reinforces member loyalty and improves margins on the items where Costco chooses to earn slightly more.

Sam's Club has invested heavily in upgrading its Member's Mark private label, repositioning it from a value brand to a quality competitor. Recent reformulations and new product launches have improved the brand's perception, but Member's Mark has not yet achieved the cult-like following that Kirkland Signature commands. The typical Costco warehouse carries approximately 3,700 SKUs (stock-keeping units) compared to Sam's Club's roughly 5,000 — Costco's more curated selection means each product gets higher volume, enabling better supplier negotiations.

This SKU discipline creates a virtuous cycle: fewer products means higher per-item velocity, which means better pricing from suppliers, which means more value for members, which means higher renewal rates. Sam's Club counters with broader selection and digital integration features like Scan & Go mobile checkout, which reduces friction and appeals to time-pressed shoppers. Walmart's advertising technology platform, Walmart Connect, also gives Sam's Club access to retail media revenue streams that Costco has been slower to develop.

For investors weighing these two companies, the choice comes down to what kind of retail bet you want to make. Costco offers a pure-play membership model with exceptional unit economics, a fiercely loyal customer base, and a management team known for disciplined execution. The stock's 54x P/E ratio prices in continued membership growth, international expansion (particularly in Asia), and the potential for periodic membership fee increases that drop almost entirely to the bottom line.

Walmart provides exposure to Sam's Club plus the world's largest retailer, with diversified revenue streams including grocery, general merchandise, health and wellness, advertising, and a rapidly growing e-commerce operation. At 47x earnings, Walmart's valuation reflects its successful digital transformation under CEO Doug McMillon and the strength of its fulfillment network.

Key risks differ for each company. Costco faces concentration risk — its US/Canada membership base is approaching saturation, and international expansion requires significant capital in unfamiliar markets. The company's reliance on warehouse foot traffic makes it more vulnerable to shifts in shopping behavior. Walmart faces margin pressure from its aggressive pricing strategy, regulatory scrutiny of its market dominance, and the ongoing cost of building out its e-commerce and last-mile delivery infrastructure.