I think it's a fee for using a personal credit card and not money from your paypal acct...If you have enough funds in your acct no fee but if partial pymt or full pymt thru credit card then they get a processing fee...just like a store has to pay a fee for people who use cards. I have an antique booth and if someone buys from my booth and uses a card I get charged the fee for them buying something in my booth.