Costco: the membership fee that makes a low-price promise credible

Costco's fiscal 2026 filings show how a fee, a narrow range and deliberate restraint turn a marketing promise into an operating model that is hard to dilute.

Most retailers treat a low price as a promotion. Costco treats it as a contract, and charges customers a fee for the right to hold it to that contract.

That arrangement is worth studying because it makes the marketing promise and the business model the same thing. When they are the same thing, the promise is unusually hard to dilute, and unusually expensive to break.

The promise, as the company describes it

Costco’s own description of its model is plain. Its annual report for fiscal 2026 says it offers “low prices on a limited selection” of branded and private-label products to produce “high sales volumes and rapid inventory turnover.”

The same filing says the company carries fewer than 4,000 active stock keeping units (SKUs) per warehouse, “significantly less than other broadline retailers.” Many consumables are sold only in cases or multipacks. Warehouses are deliberately “not elaborate.”

None of that is a slogan. Each choice is an operating constraint that makes the low-price promise cheaper to keep.

Where the money comes from

For the 52 weeks ended 30 August 2026, Costco reported net sales of $297.2 billion and membership fees of $5.9 billion. Operating income was $11.7 billion.

Two figures from that release explain the structure. Merchandise costs were $264.3 billion, which leaves a gross margin on sales of roughly 11%. And membership fee revenue was equivalent to about half of operating income.

Analysis: the comparison is not an accounting split, because fees and sales are not separately costed in the release. But it shows why the fee matters. A thin product margin is sustainable when a large, predictable stream of fee revenue sits alongside it.

The 10-K is explicit that “the membership format is integral to our business and profitability” and that growth in members, Executive upgrades and renewal rates “materially influences” profit.

Renewal is the real report card

At the end of fiscal 2026, Costco reported a renewal rate of 92.3% in the US and Canada and 89.8% worldwide. It had 42.3 million paid Executive members, and the 10-K says Executive members accounted for roughly 75.2% of worldwide net sales.

For a CMO, the instructive detail is the measurement definition. The 10-K explains that the renewal rate is a trailing calculation covering renewals seven to eighteen months before the reporting date, and that memberships expiring in the previous six months are excluded.

In other words, the headline loyalty metric moves slowly. It reflects customer judgements made over the past year, not last month’s campaign. That is a feature: it rewards consistency rather than bursts of activity.

Testing the promise with a price rise

The model faced a visible test in 2024. On 10 July 2024, Costco announced that from 1 September its US and Canadian Gold Star and Business fees would rise from $60 to $65, and Executive fees from $120 to $130. The cap on the Executive 2% reward rose from $1,000 to $1,250.

The company said the change would affect around 52 million memberships. Reuters reported that it was the first increase since June 2017.

Two details matter. First, the long gap between increases kept the fee from feeling like a routine extraction. Second, the reward cap rose with the fee, so the most valuable members received something tangible alongside the higher price.

Renewal rates remained around 90% worldwide at the end of fiscal 2026. The data cannot prove that the fee design caused that outcome, because many other factors affect renewal. It does show that the increase did not visibly break the relationship.

The marketing lesson is about restraint

Costco’s 10-K describes a warehouse that is not elaborate, with a narrow range of products and shorter operating hours than many retailers. These are choices most marketing teams would be tempted to “improve.”

That is the uncomfortable lesson. A distinctive promise often depends on refusing things customers might ask for in a survey: more choice, more convenience, smaller pack sizes. Each concession may be reasonable in isolation. Together they can erode the cost position that makes the promise credible.

The private label, Kirkland Signature, follows the same logic. The 10-K says the company believes the products are high quality, generally priced below national brands, and “generally earn higher margins.”

It also lists loss of member confidence in Kirkland Signature as a risk. A brand extension that supports the promise is also a single point of reputational failure.

Where the model is exposed

The filing names the risk directly: damage to the brand, reputation or culture “may negatively impact comparable sales, diminish member trust, and reduce renewal rates.”

When customers pay in advance for a promise, any perceived breach is felt as a betrayal of value already paid for. The fee locks in loyalty, but it also raises the stakes of every pricing, quality and service decision.

There is a second limitation. The model depends on scale, real estate and supplier terms that most businesses cannot replicate. Copying the fee without the cost structure would simply be a surcharge.

What a CMO should take from it

The transferable idea is not “charge a membership fee.” It is to ask whether your marketing promise is supported by operating choices that make it cheaper for you to keep than for a competitor to copy.

Look at your own business through three questions. Which operating constraints make your promise economical? Which “improvements” requested by customers or colleagues would quietly undermine it? And which metric shows whether customers believe the promise over a full buying cycle, rather than a single campaign?

If you cannot answer the third question, you are probably measuring marketing activity rather than the health of the promise.