What good would it be to have a telephone if no one else has one? You would have no one to call, and no one could call you. But when many people have phones, they're very useful. That's what economists call a network effect and it applies as well to payment cards. Millions of consumers carry cards with the MasterCard and Visa brands because they are widely accepted; and millions of merchants accept those cards because so many consumers carry them.
展开▼
