Amazon is urging shoppers to buy their presents early as even the most advanced online retailers battle against supply chain chaos in the run-up to Christmas.
The e-commerce giant has hired an extra 250,000 workers this year to staff its global network of warehouses - along with 100,000 temporary Christmas employees.
However, but bosses have warned that even this might not be enough to avoid disruption as Covid restrictions spark shipping delays and force millions of consumers to buy online.
Analysts have warned that if even Amazon's finely tuned logistics operation may struggle, rival bricks and mortar retailers are at risk of meltdown.
In anticipation of a landmark online shopping surge, Jeff Bezos's firm has brought forward its Black Friday discounts, began promoting Christmas deals in October, and has extended its returns window through the end of January - moves that will ease strain on its delivery network, Bloomberg first reported.
Amazon finance chief Brian Olsavsky has already warned investors that the prime shopping season might get messy.
He told analysts: “We’ll all be stretched and it’s advantageous to the customer and probably to the companies for people to order early this year."
Joshua Bamfield, director of the Centre for Retail Research, said that although businesses have hired extra couriers, the spike in home delivery will be difficult to satisfy.
“If shoppers who order later have still not received deliveries the week before Christmas, they'll be biting their fingernails. Social distancing in warehouses is also limiting retailers,” he said.
Meanwhile, Asda said shoppers are already stocking up on Christmas products, especially frozen turkeys, as online sales soared.
The supermarket said sales of Christmas trees had increased by 83pc year-on-year, festive lights by 57pc, Christmas puddings by 71pc and mince pies by 44pc, compared to the third quarter last year.
Sales of frozen turkey crowns, which typically serve three to four people, also increased by 230pc year-on-year.
Chief executive Roger Burnley said: “We have already seen a marked shift in buying patterns with customers stocking up their freezers and cupboards with festive essentials earlier than ever before, which suggests they are getting used to expecting the unexpected but preparing to enjoy themselves as much as possible.”
Asda’s total sales growth fell in the third quarter despite a continuing online surge. The Walmart-owned supermarket said like-for-like sales were 2.7pc higher in the three months to Sept 30, lower than the 3.8pc growth for the previous quarter.
Online sales soared by 72pc and operating profit also jumped as costs fell.
Patrick O’Brien, who leads the retail team at Global Data, said that most of the non-essential spend was going online and would cause “quite a problem” in the run-up to Christmas if shops did not reopen.
Online sales rose 61pc in the first week of November, data from internet industry body IMRG showed.
Andy Mulcahy of IMRG said retailers have been encouraging customers to do their shopping earlier to avoid “heavy backlogs and delays in proximity to Christmas”.
Analysts at eMarketer expect Amazon to take in about around 21pc of all Christmas e-commerce sales, worth an estimated £6bn.
An Amazon spokesman said: "We are confident in our ability to serve customers this holiday season."