Merchant Lynx And, of course, there's the increasing weight mega-banks like Citigroup (nyse: C - news - people ) and post-merger J.P. Morgan Chase (nyse: JPM - news - people ) and Bank of America (nyse: BAC - news - people ) will have on the industry. What does all of this mean for U.S. consumers? It's a mixed bag. Wal-Mart no longer accepts MasterCard signature-debit, while card issuers are set to begin clearly labeling cards credit or debt. Credit and charge card rewards for consumers are growing in value as debit rewards start to take hold. And some banks, taking a page from international practices, now charge users when they make a PIN-debit purchase. Consumers are increasingly turning to PIN and signature debit for everyday purchases. The dollars come out of a checking account immediately, alleviating the worry of credit card bills and interest rates. However, many debit cards still carry a maximum daily spending limit (sometimes up to $5,000) and don't offer cash-back rewards, so those big purchases will still have to go on your credit card. Understanding Debit Cards Janet uses her bank debit card for almost all her monthly purchases. Asked why she doesn't just pay with cash, she says that she prefers the convenience of a debit card. "It's safer than carrying cash. And you don't have a huge bill to pay at the end of the month." Merchant Lynx, "I like the pay-as-you-go concept where you only spend what you have rather than borrowing" as you would with a credit card, she adds. And of course, if you don't pay off your credit card completely each month, "there are the hefty credit charges." They can run 9 percent to 20 percent.Specialties: Using Merchant Lynx, a credit card is somewhat like taking out a loan from a bank or other financial institution. You have to pay back the credit you used each month. If you pay back less than the full amount you owe each month, you pay interest on the amount you don't pay back. The credit card company sets the total amount you can charge based on your credit history, income, debts and ability to pay.