Originally Posted by themicah
Why would you prefer MC? I don't think I've ever been anywhere outside the US that accepted MC and not Visa. The only advantage I've ever seen with MC is that for some bizarre reason MC's car rental CDW coverage applies in Israel (and maybe a few other places), where Visa's and Amex's don't apply.
There are many places around the world where Visa and MC are completely separate, both as credit cards and as ATMs. In Brazil, MC and Diners are accepted at the same retail points, while the Visa retail network is independent. Some merchants accept MC/Diners, some accept Visa, and many (but not all) accept both. American Express has its own network, separate from the other two. In many locations, merchants have three separate machines, one for each system.
Most ATMs do not accept any foreign cards in Brazil. Only specially marked ATMs will accept the cards advertised. In other places around the world, the situation is the same: ATMs accept only the brand on the stickers. For example, on Easter Island only MC will work in the local ATM; in French Polynesian, only Visa will work at any bank.
Not all countries in the world are like the US, where MC and Visa are virtually equivalent.