FAIRFAX, VA - DECEMBER 26: Josh Wise, 20, kisses his girlfriend, Savana Vestal, 18, as they take a break from shopping at Fair Oaks Mall on Monday December 26, 2011 in Fairfax, VA. (Photo by Matt McClain for The Washington Post)

A wrong guess on a size led Nancy Scott and her daughter Laura to Nordstrom at the Fashion Centre at Pentagon City, where they were waiting in line Monday afternoon to return a pair of shoes given as a holiday gift — and score some deals.

“We came to do an exchange, and we ended up buying more,” said Nancy Scott, who lives in Alexandria, while holding a stack of shoe boxes. “We are a retailer’s dream.”

Standing next to them was Dwane Weldon of Forestville, who said he was also returning shoes. He, too, planned on shopping, although he had “no idea” what to look for.

The day after Christmas — which, like Black Friday, has been anointed as a day of shopping frenzy — fell on a Monday this year, and many people didn’t have to work. Instead, throngs of people in the Washington area headed to stores.

In a recent survey by American Express, 57 percent of Americans said they planned to shop the day after Christmas this year, compared with 43 percent in 2010. Thirty-six percent said they were going to take advantage of sales and buy something for themselves; 22 percent wanted to use holiday gift cards.

The end of the year is crucial for retailers trying to eke out more sales from the holiday season, the most profitable time for stores. This year, there is some catching up to do. November was a somewhat disappointing month for consumer spending, which was up 0.1 percent, not the 0.3 percent analysts expected.

But there is hope among some retailers that this month will more than make up the difference. Holiday sales are expected to reach $469.1 billion this year, up 3.8 percent compared with last year, according to the National Retail Federation.

Aldrian Niverba and his spouse, Jamie Watts, headed straight to a register at Macy’s to return clothes. Then it would be off to the Apple store for an iPhone case.

“Today’s a purely shopping day,” said Niverba, who lives in the District.

Stores, plastered with red sale tags, opened early Monday. But the steep discounts didn’t always attract shoppers. Every item in the Bachrach menswear store at Pentagon City was marked down, up to 70 percent. Yet only a handful of shoppers were milling around inside.

“We just decided to look at the decorations . . . get out of the house,” said Kali Bracey, who was stopping in the food court with her 4-year-old daughter, Zora, and mother-in-law, Rozell Brown. “It’s not super crowded.”

In Georgetown, the mood was more mellow than manic despite the giant sale signs screaming from shop windows.

“I thought the streets might be packed, the stores might be packed. I thought I would be a frenzy,” said Courtney Biondo, 44, of Port Jefferson, N.Y., as she and her daughter, Caroline, 14, perused sale items at Gap, where merchandise was also up to 70 percent off. “But everything was orderly. Everything was calm.”

Jim McKenna, 53, of Gaithersburg could have spent the day playing golf. Instead, he trooped down to Georgetown with his wife and teenage daughters, who were hitting the sales.

“I’m just here for moral support and relaxation,” he said, lounging on a couch at Anthropologie, a women’s clothing and home furnishings chain.

His daughter Katie, 18, a freshman at Penn State, said she was surprised by the steep markdowns. “I got a sweater, a cardigan and a fancy shirt — three things at $60.”

Some shoppers, like Biondo, were from out of town. Elizabeth Greene, 48, who was visiting the area with her husband and two children, said the sales were “significantly better” than what she could find at home in Great Barrington, Mass.

“There’s much more to choose from, and the merchandise is just a lot more fun and youthful,” she said as the family stepped into Tackle Box for fish sandwiches.

Paetyn Zeamer, 13, a fan of TLC’s reality TV show “D.C. Cupcakes,” was visiting from Manheim, Pa. She said she had come to Georgetown with her grandmother, aunt and siblings “for the cupcakes and the Uggs.”

Not all stores had sales. Merchandise at the Apple store remained at full price. But Giulia Albertina, 19, visiting with her family from Lima, Peru, said a MacBook Pro laptop was a bargain.

“It’s 30 percent cheaper than in Peru,” she said, adding that she would have liked to buy clothes, too, but feared going over the baggage allowance on her flight home.

In Anthropologie, which teemed with women riffling through racks of clothing marked 50 percent off, Rob Hawkins, 31, of the District sat in a row of chairs, no doubt placed there for patient husbands and boyfriends.

He and his wife had come to Georgetown to return Christmas presents, and she had been drawn to the sales. He expected to be sitting there for a half-hour, “but I have my new iPhone to distract me,” he said — a present he did not plan to return.

In fact, as he sat, he used it to shop the Web’s after-Christmas sales.