Costco has 81M members or so, at $50&#x2F;yr that is around $4B&#x2F;yr total in membership revenue.  Their profit in the last year was $2.3B.  Thus you are correct, Costco would lose money if they didn&#x27;t charge membership fees.<p>Costco&#x27;s profit is actually really low.  $115B in sales with $2.3B in net income, so ~2% profit margin.  I guess they really do have low prices.<p>Walmart for comparison has a 3.3% profit margin in the last year on $445B in sales.  Amazon has a -0.3% profit margin on $88B of sales.