WASHINGTON — For the first time in about a decade, Arlington, Va., resident Angelica Talan did not brave the November cold for the holiday sales that many retailers launched on Thanksgiving Day this year.

Talan stayed in bed Thursday, hunting for discounts using the more than 50 new shopping apps she had download onto her iPad. By noon, she had hit paydirt, snagging a gift for her sister at a deep discount.

“I decided not to fight the crowds this year,” said Talan, who runs the blog Clarendon (Va.) Moms.

Even as millions of shoppers descended on retailers across the country Thursday, the battle for their dollars has shifted to the Web – specifically mobile devices – this holiday season.

Walmart, Target, Best Buy and other big-box retailers have redesigned their mobile sites, launched new apps and are offering some consumers customized shopping experiences. A slow website may frustrate some shoppers, so retailers designed their pages for speed this year.

This approach to online shopping is a turnaround from last year, when big-box stores were still wary of ‘showrooming’ – when customers visit a store and look for cheaper deals using their phones.

Now, they are embracing it as a way to drive sales to their own websites, analysts say. Target told its employees to approach customers using smartphones to browse for sales and steer them to the company’s mobile discounts.

Early indications show it may be working: As of 6 p.m. Thursday, online sales jumped 10 percent this Thanksgiving, according to IBM Digital Analytics Benchmark. Mobile sales accounted for 23.5 percent of the total.

“There’s more opportunity to seize more revenue if you provide a great online experience,” said Steven Dykstra, senior product manager at Compuware APM, a firm that helps retailers measure the performance of their sites and apps and whose clients include Amazon, Target, Sears and Best Buy.

Online shopping is growing, and a big chunk of that growth is from sales made on smartphones and tablets, analysts say. Surveys show that Americans are increasingly using their mobile devices to not just browse, but to make purchases, forcing retailers to pay attention.

The average retailer can expect 14 percent of holiday sales to come from mobile devices, according to a report by Adobe Digital Analytics, an increase of 40 percent from a year ago. For some retailers, the share can be as high as 20 percent to 30 percent, analysts say.

That is significant in what is expected to be a lackluster holiday shopping season, analysts said. A short holiday season, lukewarm back-to-school sales and budget-conscious shoppers have raised the stakes for retailers, who are expecting a paltry 4 percent increase in sales this year, according to the National Retail Federation.

Many opened their doors earlier than ever this year – Toys R Us opened at 5 p.m. Thursday, while Walmart and Best Buy followed an hour later – betting that the traditional Black Friday sales would not attract enough shoppers. Some retailers were offering such deep discounts that they worried it would squeeze profits.

Those discounts were enough for Yevette Lindsey, 58, who spent hours waiting outside a Best Buy in the District of Columbia to buy a 55-inch television for her new house, while her husband stayed warm in the car. Lindsey, a retiree, said she didn’t mind coming out on Thanksgiving Day to shop. “It’s fine with me,” she said. “I give thanks every day.”

Shawnna Brown, 24, spent about seven hours perched on a metal chair outside the same store. The second-grade teacher hoped to snag an HP laptop that was discounted by $200.

Tina Zhu, 22, bought all of her holiday gifts online last year, but retailers reserved some deals for their brick-and-mortor stores. So Zhu was first in line outside the Target in the District of Columbia on Thursday night to pick up an iPad air, which came with a $100 gift card, if you bought it in person.

For the consumers reluctant to leave the comforts of home on Thanksgiving, even for a deep discount, retailers are refining their Web strategy. That could make online sales, which are expected to jump 15 percent this year, the bright spot in an otherwise modest holiday season.

Chapin Traugott of Arlington has a Black Friday online shopping strategy already mapped out. “I’ve already bookmarked all the good deals,” she said.

Even so, Traugott ventured out to Toys R Us on Thursday afternoon for some early deals. “It’s kind of sad to be doing this on Thanksgiving,” said Traugott. “But the ads say 50 percent off – that’s a bigger discount than what you’d get online.”