What's more, although only 28 percent of shoppers had planned to spend more, 36 percent ended up doing so.
Fluent's study surveyed the same 2,400-plus consumers before and after the holidays.
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"Record low gas prices in December likely contributed to increased spending on gifts this year," said Jordan Cohen, chief marketing officer at Fluent.
But the break at the gas pump likely helped shoppers save on holiday travel. Cohen said that when the firm polled consumers before Thanksgiving, 36 percent said they thought they'd spend less on travel this holiday season. By the weekend after Christmas, 52 percent said they'd actually spent less.
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According to a recent study by AAA, Americans saved an estimated $14 billion on gasoline in 2014 as compared with the prior year.
"More money saved at the pump meant more money in their wallets to spend on gifts for loved ones," Cohen said.