Consumers have a love-hate relationship with their credit cards, loving the convenience but disliking the consequences. What's more, a recent study shows that consumers frequently are ignorant of the extent of those consequences.

CreditCards.com this week released "Taking Charge: America's Relationship with Credit Cards," a study conducted by GFK Roper Public Affairs that showed some alarming consumer tendencies when it comes to using plastic.

Jody Farmer, a vice president at CreditCards.com, said in a radio interview with Chuck Jaffe, MarketWatch senior columnist, that consumers simply ignore the bulk of the terms and conditions under which they deal with credit card companies. He noted that the survey showed three-quarters of Americans don't bother to read cardholder agreements.

Failing to know the terms and conditions creates other problems, Farmer said. Almost 90% of Americans do not know how long it will take to pay off a credit card bill making minimum payments. The survey showed that 55% of respondents thought minimum payments would get the job done in less than the seven to eight years that is common with typical credit terms. Another one-third dramatically overestimated how long the repayment would take.

Even when consumers know the right course of action to take, Farmer said the study showed a large gap between people knowing that an action would help their credit score and actually following that course of action. Less than one-third of the consumers who recognized that consolidating balances could be a good step actually combined their credit debt, Farmer said.

Part of the problem, Farmer noted, is that Americans appear confused about just how much they owe.

Seven in 10 people surveyed said they have less credit card debt than the average American. Obviously, not everyone in any group can be above average, and survey respondents were told that the average debt figure currently stands at around $9,300 per household.

"Obviously, some people out there are fooling themselves ... that or they just don't know how much they have in debt," said Farmer, who noted that the survey represented an accurate cross-section of the country so that it should have reflected household debt numbers that were typical.

Nearly 40% of survey respondents admitted to using their credit cards for items they could not afford, a number Farmer found high considering how many of the respondents claimed to have below-average debt.

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