If you are buying or selling an item with a stranger, you should consider ensuring the transaction by using an escrow service. These companies charge a percentage of the transaction to serve as a middleman. In short, here is how they work: The buyer mails the payment to the escrow service, which verifies the payment, then alerts the seller when everything checks out. At that point, the seller ships the goods to the buyer. After an agreed-upon inspection period (typically 2 days after the buyer receives the merchandise), the buyer notifies the service, which prints the check and sends it to the seller.