I always forget Mastercard and Visa are two separate companies, as when people talk about them, they are always said together like it's a hyphenated name Mastercard-Visa. Mastercard and Visa are always accepted either one is accepted. Discover and AmEx are totally different, and stores can accept one without the other.
It's clear that Mastercard-Visa is by design meant to be the other's alibi for not being declared a Monopoly.
It's clear that Mastercard-Visa is by design meant to be the other's alibi for not being declared a Monopoly.