According to The Nilson Report, consumers made 36 billion debit and prepaid card transactions and 20 billion credit card transactions in 2009.

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By next year MasterCard will have more credit cards issued in the U.S. than Visa, according to the Nilson Report, which tracks the industry.

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Last year, in fact, in the U.S. alone, shoppers used their debit cards an estimated 37 billion times, according to payments newsletter Nilson Report.

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According to the Nilson report, cards issued in the U.S. account for 47% of the global purchase transaction volume while Europe accounts for 23%.

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David Robinson, publisher of the Nilson Report, says there may be a business opportunity for banks in short-term, low-balance loans, which often carry higher interest rates.

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"This is an opportunity for someone big to make a move, " said David Robertson, publisher of the Nilson Report, who said Citi is the most logical buyer.

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"The only thing they can do is raise rates, " says David Robertson of the Nilson Report, who sees rates climbing--even for responsible borrowers--into the 20% range and above.

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