It's true that in recent years profits have exceeded membership revenue, but that still comprises 67% of total profit. It is still a requirement for their business model to operate, unless you're arguing that they would be comfortable with significant losses in the lean years, which I would contest.
That’s a deceptive 67%. You divided the pretax membership revenue by their post tax profit. If we use the same math we see that they get almost 70% of their profit from sales at the same time.
It falls to less than 50% when you properly compare it to pretax profits.
It also doesn’t factor in the 2% rebate that a huge number of members receive.
Costco’s total net sales for fiscal 2025 were roughly $268 billion. With executive members driving ~73.6% of that, and a 2% rebate on qualified purchases, a rough back-of-envelope estimate would place total rebates issued in the range of $3–4 billion, but Costco does not publicly break this out as a discrete figure in its financial statements.
In any case, I’m not saying it isn’t a significant source of revenue, I’m saying that “they only make money/they make most of their money from memberships” is a deceptive framing that is oft repeated. It makes it sound like they are selling things at cost when they aren’t. Their margins are in line with the grocery industry as a whole. Their pricing is an effect of low opex and volume. They make most of their profit from selling things. If they didn’t charge for membership they wouldn’t lose money.
