PHILADELPHIA — For national retailers, ’tis the season to start building an army, just like would-be rulers in “Game of Thrones.”

The recruitment began late last month with in-store and online postings to handle the holiday crunch. The National Retail Federation forecast earlier this month that holiday sales should be 3.7 percent higher this year than last.

Macy’s has plans to hire 85,000 seasonal associates companywide. Target 70,000. Kohl’s 69,000. Wal-Mart 60,000. And Toys R Us 40,000.

Retailers account for three of Maine’s top five private employers. According to 2015 Maine Department of Labor data, Hannaford is the biggest employer with 7,001 to 7,500 employees; followed by Wal-Mart with 6,500 to 7,000 and L.L. Bean is fifth with 4,501 to 5,000 workers.

Those ranks swell by at least 3,000 during the holiday season when stores elect to expand hours and ramp up for their busiest time of the year. Retail jobs, which averaged 81,600 throughout 2014, rose to 84,000 in November and 84,600 in December, according to state labor data.

Why are there so many extra workers for the holidays?

It’s twofold, says Bob Phibbs, chief executive officer of the Retail Doctor, a retail consultancy based in upstate New York.

“We all know what it’s like to wait in line at Starbucks,” he said. “Retail is a game of seconds, not minutes, because now one can easily scan and buy the item online and not have to wait in line.

“You don’t want that,” Phibbs said. “Those things typically get passed down from person to person.”

A 2015 global survey of online shoppers found that 2 percent never shop a physical store, 3 percent do it once a year, and 24 percent several times.

To better serve those online shoppers, Amazon.com hired 80,000 temporary workers last year and is expected to match that this year.

Second, there’s the pitfall of having too few staff to get through New Year’s, and the immediate days after to deal with gift returns.

“Salaried workers have to work longer, which means having to pay overtime because there aren’t enough of them,” Phibbs said. “You lose customers as a result of some of them having a bad shopping experience.

“The stakes are really high,” he said. “That’s why getting the forecasting model to predict what needs are really high is critical.

“There are a lot of moving parts – like, will you be open on Thanksgiving like last year, or stay closed? How late will you stay open, 9 p.m. or midnight? And what will the weather be like? The fewer bodies there are in the system to draw from, the more chances you will be understaffed with snow, ice or rain.

“If coverage plans aren’t there, you are in a potentially bad place because you can’t navigate that many customers or adjust your schedule with your crew on the fly,” he said.

Retailers want them typically in place two weeks before Thanksgiving.

Phibbs said memories linger of the recession of 2008, when no one was shopping, prices were slashed and retailers stopped hiring.

“Stores were empty, and the argument was whether (retailers) cut temporary help too much,” he said. “We are just coming back to what is considered normal.”

Social media has also changed the retail game.

Customers “will take pictures in the dressing room,” Phibbs said. “If you have clothes all over the floor, and they post them on Facebook and Twitter and warn others to never go there, it will hurt you.

“You have to take the threat seriously,” he said. “If they walk out of your store without buying anything, they probably aren’t coming back. You only have one shot to surprise and delight them, and get them to buy something.”

Economist Joel Naroff of Naroff Economic Advisors Inc. in Holland, Pennsylvania, who writes a bimonthly business column for The Philadelphia Inquirer and Philly.com, said holiday hiring doesn’t artificially lower the seasonally adjusted unemployment rate, now 5.1 percent nationally, because the U.S. Bureau of Labor Statistics accounts for these workers.

“We are talking about being off by maybe 0.1 percentage point even in the crazy months of seasonal hiring and firing,” Naroff said.

He described the swell in the payrolls, albeit short-lived, as “a good thing.”

“It provides temporary work for large numbers of people who desire to work either part time, or only during a portion of the year,” Naroff said. “It also provides opportunities for people who are looking for jobs to get their foot in the door.”

From the shopper’s point of view, “it becomes a must this time of year,” said David Chapman, 35, a consumer recruiting supervisor, as he shopped for shoes at a downtown Philadelphia Macy’s last week. “Everybody wants to get involved in the gift giving and receiving. It gets crazy.”

Terry J. Lundgren, CEO of Macy’s Inc., touted the 85,000 temporary jobs, the same as last year’s, and representing half of Macy’s year-round workforce of 170,000. The seasonal hires will staff all Macy’s and Bloomingdale’s stores, as well as call centers, distribution centers and online fulfillment centers.

“They fill an important niche in the employment spectrum,” Lundgren said.

For the third straight year, Target is hiring 70,000 “team members to take on important holiday roles,” chief stores officer Tina Tyler said. They include unloading trucks, stocking shelves, and setting up signs and holiday displays.

Pat Ficarotta started her Christmas shopping this month at a Kohl’s. She said she likes expanded holiday store hours because she teaches yoga in the mornings and early evenings. Huge turnoffs: long checkout and return lines.

“That’s why they need to have enough (workers) around to keep the lines moving,” said Ficarotta, 53.

“When I see how fast the lines are moving, it makes me want to come back.”