One of Costco’s most misunderstood advantages isn’t on the shelf—it’s in the membership model. The annual fee does more than grant access. It subsidizes lower prices, reshapes shopper psychology, and fuels a flywheel that drives loyalty, basket size, and conversion. Brands that understand this flywheel design Roadshows, pricing, and messaging that fit Costco’s economics instead of fighting them. Costco doesn’t rely on product margin alone. It relies on a membership-funded val