Costco Membership & Savings - Costco allows non-members to enter for free using a friend's gift card [1] - Costco strategically loses money on rotisserie chickens and hot dogs to attract customers [1] - Costco offers discounted gift cards, such as $100 gift cards sold for $80, representing a 20% discount [1] - Costco provides price adjustments within 30 days of purchase, even without a receipt [1] Costco Warranty & Return Policy - Costco offers a lifetime warranty on its products, allowing returns at any time [2]