Indeed. ACH processing is dirt cheap. I also wouldn't be surprised if the terms of ACH transactions are more favorable to PayPal than those of MasterCard/VISA.

Indeed. ACH processing is dirt cheap. I also wouldn't be surprised if the terms of ACH transactions are more favorable to PayPal than those of MasterCard/VISA. The ACH system has very strict rules guaranteeing payments once they clear the network, as opposed to the more consumer friendly rules that the card networks offer. ACH, afterall, is meant to be used by financial institutions that know exactly what they're doing.