In the past year, 23 million Americans — 10 percent of the adult population — purchased a coupon from an online site such as Groupon or LivingSocial, according to a survey conducted for the American Institute of Certified Public Accountants by Harris Interactive, reflecting a burgeoning "deal culture" that requires consumers to keep a sharp focus on their financial priorities.

The coupons were used equally for items needed, 49 percent, and wanted, 48 percent, according to the survey conducted by telephone among 1,005 U.S. adults between March 23 and March 27 in recognition of Financial Literacy Month in April. But there was disparity between the sexes. More than half of men, 53 percent, said they bought coupons for products or services they wanted, while an equal percentage of women got coupons for items they needed.

"The crux here is 'need' versus 'want,'" said Jordan Amin, chairman of the National CPA Financial Literacy Commission. "We all love a great deal — and we encourage consumers to pursue any opportunity to save on items they need. A purchase, though, is always an exercise in prioritization. Spending on too many wants, no matter how great the perceived value, is lost opportunity for retirement or other savings."

Indeed, Americans are struggling to sock away money for the future, according to the survey. More than half of Americans, 56 percent, are unable to save, and 4 in 10 working adults say they'll never afford retirement. The challenge of saving is exacerbated now by rising fuel and food prices. Six in 10 adults have changed their behavior to contend with rising gas prices. Forty-eight percent of Americans have modified their behavior to deal with rising food costs.

In the face of these challenges, an increasing number of retailers are turning to online deal sites and flash sales to attract consumers. According to the survey results, such offers are especially appealing to younger shoppers. Americans aged 25 to 34 are more likely than any other age group to have purchased a coupon from Groupon, LivingSocial or another online deal site within the past year.

"In our growing deal culture it's important that consumers take a step back," Amin said. "When they encounter these offers they need to think through their needs, the actual value of the deals and the financial tradeoffs that come with spending money instead of saving it.

"Money doesn't come easily," Amin continued. "We want to make sure it doesn't go easily, either."