PayPal charges a fee because it is a for-profit business that generates income by charging fees on transactions. These fees help PayPal cover the costs of processing payments, maintaining security, providing customer support, and offering services such as fraud protection and dispute resolution. Additionally, the fee revenue enables PayPal to maintain high service levels, pay employees, and invest in innovative payment methods. The fees also include costs that PayPal incurs from banks and card networks involved in processing transactions. Specifically, PayPal charges fees mainly to merchants and businesses for processing payments, which typically range from about 1.29% to 2.9% of the transaction amount plus a fixed fee per transaction, depending on the country and type of transaction. For personal consumer transactions like sending money to friends and family, fees are often waived unless currency conversion or international transfers are involved. In summary, PayPal's fees exist to support its business model, operational costs, and service guarantees, while also compensating for third-party processing expenses and risks associated with online payments.