The 2015 Coinstar Holiday Survey, which was conducted in October by Kelton Research to explore the holiday spending habits of consumers, revealed a number of surprising truths about the average seasonal shopper. Here's a look at some of the more interesting tidbits.

We're shy about using gift cards

Most people love the versatility of gift cards, but a shocking 37 percent of survey respondents confessed that they didn't redeem all of the cards they received in 2014. Although federal law enacted in August of 2010 mandates that gift card balances cannot expire for at least five years after purchase and inactivity fees cannot apply until a card remains unused for one year, different states have different rules regarding redemption.

The brass tacks? It's probably better to use it when you get it so it doesn't wind up buried in the bottom of a drawer for five years.

Americans really love plastic

Although financial gurus like nationally-recognized money-saving expert Andrea Woroch advise against doing so, 49 percent of polled gift-givers (versus 41 percent in 2014) plan to use a credit card over cash or gift cards to make purchases. If you must use plastic, Woroch advises using a card with a "really good reward program" and using points accrued from your account to purchase gifts.

That's part of Maryland shopper Jennifer Biddison's plan of attack. She uses Amazon-branded card to earn Amazon gift certificates that she can turn around and use on the site.

The suburban mom of three is especially keen on the site's Lightning Deals, which are products offered for a limited time at a significant discount.

Too many shoppers overspend

A whopping 62 percent of those who establish a budget for holiday shopping admit that they go over the amount they plan to spend. Woroch encourages shoppers to think ahead and account for unexpected expenses, like extra groceries for out-of-town visitors, to keep from busting the budget.

After all, as Diamond Dust Designs owner Gretchen Cavell notes, "those credit card bills will roll in come January" and you'll have to find a way to pay them off.

The light at the end of the financial tunnel

Finally, a happy fact: according to Coinstar data, consumers estimate that the spare change laying around their homes probably amounts to roughly $29, but they're wrong. In truth, customers trade in an average of $62 when converting coins to no-fee eGift cards.