You're absolutely right. The processor (in this case Square) takes the smallest portion of the 2.75% with Visa/Mastercard taking the second highest, and the lar

You're absolutely right. The processor (in this case Square) takes the smallest portion of the 2.75% with Visa/Mastercard taking the second highest, and the largest portion (by a large margin) going to the issuing bank. Here's an illustration: http://upload.wikimedia.org/wikipedia/commons/3/37/Gao-report-on-interchange.gif http://upload.wikimedia.org/wikipedia/commons/3/37/Gao-repor...