So the terms of that agreement would likely look different and vary from carrier to carrier, and vendor to vendor.

From experience, I can tell you that is the case with credit card processing as well. Bank rates and transaction fees vary, as do rates charged by web vendors. With web vendors, I have seen rates as low as 4% charged for credit card services up to as high as 15% – and that is often on top of the fees charged by the banks.

This is an area where campaigns may want to shop around more before selecting a vendor, bargain to get the best rate, and disclose to potential donors what the rates are before they make a donation.