Costco's High Wages and Its 4,000-Item Limit Are the Same Decision

Walk into a Costco for paper towels and you leave with a kayak. This is not an accident of poor self-control. It is the most carefully engineered impulse in retail - a rotating slice of the floor, here today and gone before you can think it over, that the company's co-founder named the 'treasure-hunt' atmosphere.⁵ Now look up from the kayak. The person who rang it up may be earning close to $32 an hour, in an industry that treats its floor staff as interchangeable and disposable.² Two strange facts about the same store. Almost everyone files them under separate folders: one is clever merchandising, the other is corporate kindness.

The story everyone tells is that Costco is a generous company that happens to merchandise well. The truth is the reverse of two separate virtues. The thin product range and the fat paychecks are not parallel; they are linked in a single loop, and pull either one out and the other stops working.

Here is the thesis in one line: the 4,000-item limit is what pays for the wages, and the wages are what make the treasure hunt feel curated instead of chaotic. A constraint, a payroll, and a shopping experience that look like three decisions are one.

How a missing 26,000 products buys you better cashiers

Start with the constraint, because it is the engine. A supermarket carries about 30,000 items; a Costco warehouse carries fewer than 4,000.¹ That gap is not laziness - it is leverage. When you sell one brand of ketchup instead of fifteen, every case you buy is a bigger case, every negotiation a bigger order, every supplier a captive supplier who knows the alternative is your whole national volume going to a competitor. Fewer doors to walk through means you can demand a far better price at each one — Costco's concentrated volume gives it roughly ten times the per-SKU purchasing power of a broad-assortment rival, often making it the single largest buyer for any item it carries.⁹ The narrow range manufactures buying power the same way a funnel manufactures pressure: by refusing to spread out.

That manufactured margin is the budget. It is what lets Costco run merchandise at famously thin markups and still throw off real profit - net income rose to $8.1 billion in fiscal 2025 on $269.9 billion of sales.⁴ And it is what makes the wages affordable rather than charitable. Costco lifted starting pay to at least $19.50 an hour and pushed top-of-scale clerks to $31.90, with raises already locked in for 2026 and 2027.² You cannot pay that on a sprawling 30,000-item floor with razor-thin per-item leverage. You can pay it when 4,000 disciplined choices have already done the heavy lifting on cost.

The wage is a retention machine, and retention is the secret ingredient

Pay people well above the market and a strange thing happens: they stop leaving. Costco's own People Systems director has said that, after the first year, annual turnover runs between six and seven percent - against a retail-industry average near 60%.³ Read that again. The typical retailer churns more than half its floor every year and starts over with strangers. Costco keeps its people. That is not sentiment; it is the operating advantage hiding in plain sight. Replacing a worker is expensive, but the deeper cost of churn is invisible: a floor full of new hires who do not yet know where anything is, what is good, or what just arrived.

Now the loop closes. Roughly a quarter of those 4,000 SKUs are constantly changing - the limited-run novelties that make the treasure hunt a hunt at all.⁵ A rotating floor is, by definition, a floor nobody has memorized. It only feels like a curated discovery rather than a junk-drawer of clearance if the staff know what just landed, can tell you it is genuinely a deal, and can find it. That requires tenure. A floor of one-year veterans makes the surprise feel intentional. A floor of last-week's hires makes the same surprise feel like chaos. The treasure hunt is not a merchandising trick layered on top of the staff - it is something only experienced staff can stage.

This is why the lineage matters. Jim Sinegal spent more than two decades learning the warehouse discipline from Sol Price before co-founding Costco in 1983 with Jeffrey Brotman, who brought the capital and the Seattle retail network.⁶ What Sinegal carried out of Price's operation was not a pricing gimmick - it was a conviction that the constraint and the people are the same lever. The same man who coined 'treasure hunt' is the one who refused to treat labor as a cost to be minimized. He understood they were one decision, which is why he reportedly sat down with Jeff Bezos in 2001 and walked him through the entire model — the membership logic, the supplier discipline, the value-first doctrine — over coffee in Bellevue, Washington.¹⁰

Isn't this just a profitable company that can afford to be nice?

The honest objection is that the causality might run backwards: Costco is enormously profitable, so it can splash out on wages, and the loop I've described is just a flattering story drawn around a rich company's discretionary spending. That is the strongest counter, and it deserves a real answer. The answer is that the high-wage model has been studied precisely because it is not discretionary largesse - MIT's Zeynep Ton frames Costco as the proof case for a 'good jobs strategy,' the demonstration that high wages and low prices are not enemies but can be made to fund each other.⁸ A company that pays well only because it got rich would cut pay the moment margins tightened. Costco does the opposite: it locks in raises years ahead, treating wages as fixed infrastructure rather than a dividend of good times.²

There's a second, quieter correction worth making, because it's where most people's mental model is wrong. The folk wisdom is that Costco earns nothing on merchandise and lives entirely off membership fees. Not quite. Membership revenue reached $5.3 billion in fiscal 2025 - crucial, and a disproportionate slice of profit - but membership fees alone do not account for all of Costco's profitability — the merchandise itself runs at thin but genuinely positive margins, with markups typically capped around 14 percent, and the fees and merchandise economics work together rather than one fully replacing the other.⁴ The fees underwrite the low prices; they do not replace the business. The machine still has to work as a machine.

So the kayak by the paper towels and the $31.90 on the cashier's pay stub are not two stories about Costco. They are the same story, read from opposite ends. The thin shelf squeezes out the buying power that funds the wage; the wage holds the people who make the thin shelf feel like a discovery instead of a clearance bin; and the discovery is what brings you back to find the next thing you didn't come for. Most retailers treat selection, payroll, and experience as three budgets to fight over. Costco figured out they were one decision - and then declined to make it twice.