Business sense / Costco / FY2025

The discipline behind
the bargain.

Costco’s advantage is a set of operating choices that reinforce each other. The useful casing question is what happens when you change one.

WAREHOUSE ASSORTMENT<4,000

active SKUs per warehouse

FY2025 · core warehouse business10-K · Business ↗

01 / Operating choices

A narrow range changes the whole operation.

Read the chain from assortment to the member proposition.
  1. 01 · CHOOSE

    Concentrate demand

    Fewer than 4,000 warehouse SKUs; 9,000–10,000 online.

    Reported assortment scope
  2. 02 · MOVE

    Buy direct. Cross-dock.

    Large supplier shipments move through depots to warehouses with fewer handling steps.

    Reported distribution method
  3. 03 · DELIVER

    Protect the value proposition

    Inference to test: purchasing and handling savings can fund lower prices, rather than only higher margins.

    Analytical link, not a measured causal effect
  4. 04 · RETURN

    Make renewal worthwhile

    89.8% worldwide renewal; 92.3% in the U.S. and Canada.

    FY2025 trailing measure; not current-month retention
10-K · Business: assortment, distribution, membership ↗

The tempting mistake

A buyer might add variety to capture more demand. But new SKUs also spread volume across more products, use working capital and add handling. “More choice” is a hypothesis about customer value, not a free source of growth.

The research question

Which customers leave because a product is missing—and how many would switch to an existing option? That distinction separates incremental demand from substitution.

Follow the money →

02 / Financial anatomy

Membership matters. It is not the whole profit.

FY2025 operating-income bridge · USD billions · arithmetic from reported line items.

From merchandise spread to operating income
$30.026bn
Net sales minus
merchandise costs
−$24.966bn
SG&A
+$5.323bn
Membership
fee revenue
$10.383bn
Operating
income

Blue = positive amount; rose = expense; deep blue = total. Vertical positions show the running balance; rounded bar geometry, exact labels.

10-K · Consolidated statements of income ↗

The residual before adding fees is $5.060bn. This arithmetic is not a reported standalone merchandise segment profit: Costco does not allocate all membership-related costs into a separate business here. Fee revenue is recognized over the membership year.

Method: $269.912bn net sales × basis-point change ÷ 10,000. Ten basis points equals approximately $269.9m. This isolates one lever; actual volume, mix and costs can respond.

Profit and cash follow different clocks →

03 / Working capital

The customer can pay before the supplier does.

Costco says it often sells inventory before supplier payment is due. The sequence matters more than a generic “low inventory” claim.

Illustrative timing—not Costco’s reported inventory or payable days
  1. Day 0Receive stockInventory and a payable arise.
  2. Day 20Collect from customerCash arrives after the assumed sale.
  3. Day 30Pay supplierCash leaves ten days later.

Illustrated funding interval: 10 days between collection and payment.

10-K · Business: inventory and supplier terms ↗

What to calculate

Cash conversion cycle = inventory days + receivable days − payable days. Use consistent periods and average balances. Fast inventory movement alone does not prove a negative cycle.

What could break it

Slow-moving new items can delay collection. Shorter supplier terms can accelerate payment. Test the two clocks together before recommending an assortment expansion.

Try the decision yourself →

04 / Apply the mechanism

Would you add 1,000 SKUs?

Original practice case, not Costco guidance or a forecast. Assume one warehouse, one year, and no price changes to the existing assortment.

DEMAND

What is truly new?

Sales of added items minus sales displaced from existing items.

ECONOMICS

What survives the costs?

Incremental contribution minus extra handling, labor and space costs.

CASH & RISK

What must we fund?

Inventory and terms, markdown risk, and a reversible pilot.

A worked decision bridge

Assume $2.0m new-item sales, 40% cannibalization, 15% contribution margin on both added and displaced sales, and $220k extra annual operating costs.

  1. Keep only incremental sales$2.0m × 60% = $1.2m
  2. Convert to contribution$1.2m × 15% = $180k
  3. Subtract added operating costs$180k − $220k = −$40k

Decision: Do not roll out on these assumptions. At unchanged sales and margin, cannibalization must be below roughly 26.7% to break even, before financing costs and initial investment. Pilot a smaller selection to test substitution and handling.

SKU
A distinct stock-keeping item; a size or color can be a separate SKU.
Cannibalization
New-item sales that replace sales the business would already have earned.
Basis point
0.01 percentage point. Ten basis points = 0.1 percentage point.

Practice the profitability framework →