⚠ Renewal Is the Only Vote Members GetModerate threat

The mathematics of a subscription are unforgiving in one direction. At a 92.3% renewal rate the average membership lasts about thirteen years. At 88% it lasts about eight. Nothing visible happens in the quarter the rate moves; comparable sales stay fine, the warehouses stay busy, and the damage shows up years later in a smaller base paying a fee that had been assumed to compound.

Costco's rate has already moved. United States and Canada went 92.3% at the end of fiscal 2025 to 92.2% at the end of the third quarter of fiscal 2026, worldwide 89.8% to 89.7%¹. The company's explanation is specific and testable: a higher number of memberships sold online, including through digital promotions, has entered the calculation, and those renew at a slightly lower rate on average. If that is the whole story, the rate should stabilise once the promotional cohorts wash through.

The reason to keep watching is that the measure itself is generous. It is a trailing calculation covering renewals seven to eighteen months before the reporting date, and it excludes memberships expiring in the six months before period end regardless of whether they were renewed². The membership counts themselves include memberships that expired and were not renewed within the prior twelve months. Neither is improper — both are disclosed — but both smooth a series that would otherwise be the sharpest early-warning signal the company publishes.

What would falsify the facet is a renewal rate that keeps drifting for four consecutive quarters after the online cohort has cycled through, particularly if it drifts while the fee is unchanged. That would say the fee had stopped being obviously worth paying, and the whole edifice above it — the 11% gross margin, the $32 wage, the returns policy — is only affordable while it obviously is.