Your source, or is this pure speculation? Even Walmart can&#x27;t negotiate Visa&#x2F;MC interchange fees.[1] And they do ~400X Square&#x27;s volume. It&#x27;s not just a matter of merchant&#x2F;processor size. Once enough consumers have adopted it as their primary&#x2F;only card, the card network has an extremely strong position. (This is why AmEx rates are more negotiable; it&#x27;s usually an alternate card.)<p>[1] They do lawsuits instead. <a href="http:&#x2F;&#x2F;www.reuters.com&#x2F;article&#x2F;2014&#x2F;03&#x2F;27&#x2F;us-walmart-visa-lawsuit-idUSBREA2Q2BJ20140327" rel="nofollow">http:&#x2F;&#x2F;www.reuters.com&#x2F;article&#x2F;2014&#x2F;03&#x2F;27&#x2F;us-walmart-visa-la...</a>