NEW YORK — Power up and shop.
Millions of Americans took advantage of online deals ranging from free shipping to hundreds of dollars off electronics and half-price clothing Monday, which was expected to be the busiest online shopping day of the year.
The spending surge on so-called Cyber Monday came after a disappointing holiday weekend in stores. And it showed that Americans are increasingly comfortable buying items on tablets and smartphones.
Early results indicated online shopping was up 17.5 percent compared with the same time last year, according to figures by IBM Benchmark. Mobile devices accounted for more than 29 percent of all online traffic.
Brandon Harris, 27, from Memphis, Tenn., started shopping at midnight Sunday and by Monday had spent about $300 and completed half of his Christmas shopping, including a Barbie doll for his niece and a TV for his mother.
"I haven't shopped for a Christmas present in a store in three years," he said, making purchases from his iPad instead. "It's a lot more convenient to be at home and shop."
The National Retail Federation, a trade group, predicted more than 131 million people will shop online Monday, up about 2 percent from last year.
Meanwhile, UPS expected to pick up more than 32 million packages Monday, about a million more than Cyber Monday last year.
And research firm comScore expected Cyber Monday sales of $2 billion, up from about $1.47 billion last year.
Online sales account for about 10 percent of total holiday spending, which is expected to grow about 3.9 percent to $602.1 billion for the months of November and December.
Joel Anderson, president and CEO of Walmart.com, said he anticipates Cyber Monday to be the site's busiest day ever. He said 2013 is the "tipping point" for mobile traffic, which includes smartphones and tablets.
More than half of Walmart.com's traffic came from smartphones and tablets on Thanksgiving and Black Friday, Anderson said. And he expected the same to be true on Monday.
"2013 is the year online went mobile," he said.