There are a few key differences between just paying with a credit card and PayPal. First, when you pay with a credit card, the merchant has to pay a fee to the credit card company. With PayPal, the buyer pays the fee, which is why it can sometimes be cheaper for the buyer. Second, when you use a credit card, your purchase is protected by the credit card company if there are any problems. With PayPal, the buyer's protection only covers up to $500.