Meanwhile, some bricks-and-mortar stores are extending early morning bargains that had been offered on Saturday through Wednesday.
Amazon.com has extended the cutoff for standard shipping by one day through Monday. Macy's Web site is offering free shipping through Monday, and J.C. Penney through Tuesday.
The moves are a bid to capture business from snowed-in shoppers in the final days before Christmas. The weekend before Christmas is one of the busiest of the year, but snow that stretched from the Carolinas to New England closed malls and kept Americans off treacherous roads.
Retailers aren't the only ones giving customers a reprieve after the snow storm. CBS News correspondent Bianca Solorzano reports that many airlines, including US Airways, JetBlue, Delta and some others, perhaps moved by the holiday spirit, are relaxing or even waiving fees and any price differences associated with rebooking flights.
Meanwhile, Web retailers saw heavy traffic during the weekend. On Friday and Saturday, online sales rose 24 percent from the same days last year, Web research company Coremetrics said. It also showed the average shopper spending and ordering more on Saturday, when the weather's effects were deepest, than Friday.
Retail Web traffic peaked at 2.9 million visitors per minute Saturday night, according to the Akamai Retail Net Usage Index. That was up from 1.9 million on the Saturday before Christmas in 2008, though that day - Dec. 20 - was closer to Christmas than this year.
Online spending has been a bright spot. It grew 14.4 percent after Black Friday through Dec. 12, according to a release Sunday from MasterCard Advisors' SpendingPulse, which estimates sales in all payment forms, including cash and checks.
Shoppers are likely to give retailers, both online and bricks-and-mortar, a frenzied last few days before Christmas after digging out the snow. There were already early signs of customer traffic picking up at malls, according to reports.
Marshal Cohen, chief retail industry analyst at market researcher NPD Group, who surveyed crowds at malls on Long Island, early Monday, said that the shoppers at the Walt Whitman Mall in Huntington, New York, were "serious about shopping. They're making up for lost time." He added that big chains hadn't sold out of their early morning deals on Saturday so they were extending those bargains.
Karen MacDonald, spokeswoman at Taubman Centers, said that based on a survey of four malls, traffic is picking up, and she expects the day to be very busy.
Les Morris, spokesman at mall operator Simon Property Group, noted the mall operator is thinking extending hours beyond what was planned for early this week to accommodate customers.
"The expectation is people have waited until the last minute but they have not waited until the last day," said Wally Brewster, senior vice president for marketing and communications at General Growth Properties Inc.
More Americans have put off their shopping this year as they look for more deals. The company, which has more than 220 malls, figures about half of its shoppers are last-minute ones, up 10 percent from last year.