(Bloomberg) -- Extensive delays at the U.S. Postal Service have pushed millions of Americans to do the one thing they swore they wouldn’t this holiday season: shop inside stores.

On Dec. 24, parking lots filled across the U.S. with shoppers grabbing last-minute items after finally admitting to themselves the in-transit orders they placed online days or weeks earlier might not make it in time for Christmas.

“Christmas comes whether the postal service does or not,” said Simeon Siegel, analyst at BMO Capital Markets. “At the end of the day, Santa has to deliver. If that means that the postal service or port stoppages or any other supply bottlenecks are preventing items from getting to the tree, there’ll been a last-minute attempt to find something.”

The rush to the mall is good news for retailers, many of which are still trying to make up for the sales they lost when shuttered during lockdowns earlier this year. In-person purchases carry higher margins than delivered items, plus shoppers are more likely to throw in “something extra” at the last second when gift-hunting in store, boosting basket sizes -- and companies’ net sales.

Online Surge

Americans have largely shunned in-person shopping this year to steer clear of potential virus exposure. Seasonal shopping started weeks earlier than usual and more of the volume moved online, resulting in Black Friday visits dropping 52% compared to a year ago, according to data from Sensormatic Solutions. It was also down sharply over Super Saturday weekend, traditionally the last shopping surge before Christmas.

But as the post office reports “unprecedented” volumes and large swaths of its workforce out due to Covid-19, those packages are piling up in delivery trucks and processing plants, rather than under the tree. With delivery statuses lingering “in-transit” and only about 12 hours until Christmas, some U.S. shoppers decided they had to mask up and hit the stores after all.

“There’s surprisingly a lot of people heading out last minute,” Gabriella Santaniello, founder of retail research firm A-Line Partners, said after visiting stores near Los Angeles in the final days leading up to Christmas. “Yesterday, I was at one mall and it was the busiest mall I’ve been to since pre-pandemic.”

That marks a big change from just a few days ago, when the Super Saturday crowds never materialized. Activity during Super Saturday and Black Friday weekends was so low, in fact, Sensormatic Solutions had to revise down its foot-traffic forecast for the entire holiday season. That’s because as of last Saturday, shoppers still held onto hope their orders would make it. No longer.

Line Out the Door

“Shipping delays have been an issue this year, which is resulting in consumers shifting from online to in-store to make their last minute purchases,” according to the International Council of Shopping Centers. Less than half of consumers had finished their holiday shopping heading into last weekend, it said.

Mackenzi Farquer, owner of Lockwood, a small chain of boutiques in New York City, is experiencing the boom first hand. She said there was a “block-long line” outside her Astoria, Queens, location on Christmas Eve when she arrived at work at 10 a.m. The day before was the busiest her store has been since the pandemic began, and she’s had to turn away shoppers at closing time.

“To me, as a retailer, it’s shocking,” she said. “We close at 6 p.m. tonight and I suspect we’ll have to tell people that unfortunately, they can’t come in. Last night we had to close even though there were folks still in line waiting to get in.”

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