When walking in to a department store and making a purchase of an item, that is the acceptance of contract. A customer is accepting the stores terms and conditions regarding the returns and warranties. If you purchase an item at a garage sale, a customer goes into a sales contract but the item is purchased as "at is" and no returns will be accepted.If a item is purchased at an action, the contract is finalized when the highest bidder pays the price that was accepted as the highest bid on the item. The type of contracts affects the consumer when an item is faulty specially when it is purchased at a garage sale or action. Since these type of purchases are very limited and items are sold "as is" and would have to keep a faulty item. When in a department store, they would let you return, replace it or get credit for the faulty item.