I think the emergence of debit and credit cards has been one of the most important developments in the support of commerce over the past 30 years or so. Of course, the Visa and MasterCard companies have probably been the biggest beneficiaries of this change, but I think society and free markets have been big winners as well. It is now a rarity to see someone whip out a checkbook to pay for groceries or other products in a store. This is because using a card is so much more convenient. With check cards, at the end of the month, consumers get a statement that tracks all of their purchases which obviates any need to record entries in a checkbook.
On the merchant side, there have been significant developments too. Although Visa and MasterCard are undoubtedly the 80 pound gorillas of the bank card market, there still remains a lot of competition. This competition has resulted in cheaper transaction rates and more efficient card processing systems. Providers now focus on the best credit card processing systems, which benefit both the merchant and the consumer. Now, most credit card issuers offer merchant accounts that provide a simple and convenient way for business owners to manage their customer accounts.