Costco: The Membership Flywheel

Costco collected $4.828 billion in membership fees during fiscal 2024. That was equivalent to roughly 52% of its $9.285 billion in operating income; the comparison does not make every fee dollar pure profit. By year-end, Costco had 76.2 million paid members, and 90.5% of eligible members worldwide renewed. Together, those figures reveal a financing mechanism embedded inside a retailer.

The mechanism shapes what happens on the shelf. Membership revenue gives Costco room to preserve a narrow merchandise margin; visible savings support renewal, and renewal concentrates purchasing volume.

A conventional retailer earns its economics mainly from the spread between the cost of goods and the selling price. Costco has a second revenue stream collected before a member fills a cart. In fiscal 2024, membership fees rose 5% to $4.828 billion, while the company reported a gross margin of 10.92%. Both figures appear in Costco’s FY2024 Form 10-K.

The fee does not subsidize every item dollar for dollar. Costco still needs merchandise sales to cover product, labor, occupancy, freight, and other operating costs. The separate stream changes the boundary of an acceptable decision. Management can protect a visible saving even when more margin on that item would improve the current quarter.

That freedom only has value if members receive it back through savings they can repeatedly observe. A retailer that collects an annual fee and then prices like everyone else has added a charge without improving the underlying bargain. Costco converts part of the fee advantage into a durable price position, giving the contract a reason to exist beyond access.

Low markups would be fragile inside an undisciplined assortment. Every additional product adds forecasting, handling, shelf space, and markdown risk, while dividing demand among more suppliers. Costco deliberately carries fewer stock-keeping units than broad-line retailers and concentrates purchases on fast-selling items, a model described in the company’s annual filing.

Concentration changes the negotiation. Costco can direct a large share of category demand toward one selected national brand or a Kirkland Signature alternative. A supplier that wins the slot receives meaningful volume; Costco gains leverage over price, pack size, quality, and delivery terms.

The constraint also simplifies warehouse operations. Fewer choices mean fewer replenishment decisions and more sales per item. Costco reported that its high sales volume and rapid inventory turnover often let it sell inventory before payment to vendors became due. Efficient working capital is therefore an operating result of assortment discipline, not a separate financial trick.

Subscription businesses often measure loyalty through passive retention. Costco asks for an explicit annual payment, so the member has a recurring moment to reconsider the relationship. The worldwide renewal rate was 90.5% at the end of fiscal 2024; the United States and Canada reached 92.9%, according to the same 10-K.

Those rates reflect accumulated experience rather than one spectacular discount. A member sees savings across fuel, groceries, appliances, travel, pharmacy services, or a handful of large purchases. Pack sizes and limited assortment make some comparisons imperfect. The warehouse must still preserve a credible pattern: the trip and fee should repay the household over time.

Executive membership makes that relationship measurable at the high end. Costco had 35.4 million paid Executive members in fiscal 2024, and they accounted for approximately 73.3% of worldwide net sales. The upgraded tier rewards qualifying purchases, which encourages members with heavier spending to consolidate more of it at Costco. Their activity supplies volume while their renewal decision tests whether the value remains visible.

A renewed member begins the next membership year with money already committed and a reason to return across many categories. Costco does not know the contents of the next basket, but it knows the size, renewal behavior, and spending history of a large member base. That information gives buyers a firmer demand signal than occasional store traffic alone.

Predictability strengthens purchasing terms because suppliers can reach concentrated demand through a relatively small number of placements. The relationship becomes especially valuable when Costco can support a large order, move it quickly, and limit the operational complexity surrounding it. Vendors trade some unit margin for reach, velocity, and a clear path to the customer.

The Executive cohort deepens this effect. Its 35.4 million paid members represented less than half of paid memberships while generating nearly three quarters of worldwide net sales. Heavy spenders therefore make the demand base more economically dense, allowing Costco to negotiate around substantial expected volume instead of undifferentiated footfall.

Stronger terms can improve price, product specifications, package economics, or supply reliability. Costco then faces a capital-allocation choice at the item level: retain the advantage as margin or pass enough of it to members to reinforce the next renewal. The system compounds when the member can observe the return.

Kirkland Signature gives Costco another route. The private label can set a quality and price reference inside a category while giving the company more control over specifications. It also disciplines national brands: a weak branded offer competes with an alternative that Costco can shape around member value.

The loop closes through restraint. Lower prices help earn trust, trust supports renewal, renewal concentrates volume, and volume improves buying power. Management must keep circulating part of the gain. If too much value stops at the retailer, the next renewal becomes harder and the purchasing advantage eventually weakens.

Concrete floors, pallet displays, bulk packaging, and an annual fee are easy to observe. The balance among them took years to build. A new club starts with fewer members, which produces less volume per item and weaker terms from suppliers. Those terms make a dramatic price advantage expensive to sustain precisely when the entrant still needs to prove the fee is worthwhile.

Trust adds a second barrier. Members have learned what Costco’s limited selection implies: buyers screened the item, negotiated aggressively, and expect it to move quickly. An imitator can reduce choice overnight, but customers may interpret the result as a thin assortment rather than confident curation.

The final barrier is managerial. Costco’s system rewards decisions that preserve renewal economics even when another choice could lift near-term merchandise margin. A rival measured mainly on margin expansion will struggle to maintain that discipline through a difficult quarter.

Price credibility. The fee becomes vulnerable when members repeatedly find comparable baskets cheaper elsewhere. Occasional misses are inevitable; a sustained loss of confidence changes renewal from an economic choice into a habit waiting to end.

Assortment creep. More products may satisfy more requests while reducing volume per item and increasing inventory complexity. Once selection expands faster than demand, Costco loses part of the purchasing concentration that supports its prices.

Renewal deterioration. A lower renewal rate removes both fee revenue and expected merchandise demand. The damage travels around the loop: weaker demand reduces purchasing leverage, which makes the price promise more expensive to maintain.

A recurring fee becomes strategically useful when it changes the economics of the core product. It can fund lower prices, better service, stronger guarantees, or infrastructure that improves with retained customers. The benefit must remain observable enough to justify the next payment, and retention must improve the company’s ability to deliver it. If recurring fees rise but the core product does not become cheaper, better, or harder to leave, the business has added a toll—not a flywheel.

Historical cutoff: June 29, 2025. No event or financial result published after that date is used in this analysis.