COEUR d'ALENE - Take gift cards and unexpected Christmas cash, mix it with unwanted gifts and time off, and you have the perfect recipe for Black Friday II.

Just like the day after Thanksgiving, the day after Christmas has become one of the busiest shopping days of the year, retailers, shoppers and experts agree.

But unlike the post-Turkey Day rush, which preaches sales, sales, sales, a perfect storm of reasons brings shoppers out for another round of holiday splurging.

Whether returning less than ideal gifts, spending Christmas cash or redeeming gift cards that were stocking stuffers the day before, people have a number of reasons why Dec. 26 is becoming a shopping free for all.

"This is usually one of the busiest days," said Adam Tait, manager at Target in Coeur d'Alene, as he took a break from helping swarms of customers in his store Wednesday. "It always happens that way for us."

In fact, the store opened an hour earlier than usual, 7 a.m., to prepare for the crush. Add in old-fashioned draws, like end of the year clearance sales, and it becomes all the busier, he said. Plus, people have time off this week, so finding time to get to the stores is that much easier.

Like for Jared Powell, North Idaho College student on winter break, who perused the shelves at Target. He didn't want to return a Christmas gift, rather augment one. He received an Xbox, and spent Wednesday looking for a good Kinectic game to go with it. He doesn't do the post-holiday shopping splurge, he said, he just wanted to pick up that one thing.

"It's a nice thing," he said. "I'm just a college kid who wants a little something else."

How big is after-Christmas shopping getting?

According to the Associated Press, the final week of December can account for about 15 percent of the month's sales for stores across the nation, with the day after Christmas providing a big chunk of that.

"This is bigger for us than Black Friday," said Julie Vucinich, manager of the Ski Shack in Hayden, who arrived at her store Wednesday morning and found five people waiting for the store to open. "This is like our primetime."

Another big attractant for shoppers: Clearance prices - especially for anything with a Christmas theme. Sharon Carvo, another Target shopper, loaded up on wrapping bows, so she'll be set for next year, or the next birthday.

"It's more crowded than normal," she said of the rush. "It got a little crazy in line at the end."

Despite huge discounts and other incentives that stores offered leading up to Christmas, U.S. holiday sales have been the weakest since 2008, when the nation was in a deep recession, according to the AP.

In the run-up to Christmas, analysts blamed bad weather for putting a damper on shopping. In late October, Superstorm Sandy battered the Northeast and mid-Atlantic states, which account for 24 percent of U.S. retail sales. That coupled with the presidential election, hurt sales during the first half of November.

Still, just what kind of holiday season it was financially won't be known for sure until after New Year's. The National Retail Federation estimated that holiday cash registers would ring up $586.1 billion, up 4.1 percent from a year earlier. But in recent weeks, merchants have expressed doubts about hitting that mark.