Early estimates of Cyber Monday, the biggest online shopping day of the year, showed sales may reach $2 billion and a growing portion of that may come from the pockets of a record number of mobile shoppers.
As of 2 p.m. EST, payment system PayPal had a 196 percent increase in mobile payment volume on Cyber Monday 2012 than Cyber Monday 2011. On Black Friday, the increase in the number of people shopping on their mobile devices was stark for PayPal as well as auction site eBay, which owns PayPal. On Friday, there was a 153 percent increase in mobile volume transactions compared to Black Friday last year. PayPal's volume increased almost three-fold, 193 percent, compared to last year's Black Friday.
The annual event is increasingly becoming Cyber Week instead of a one-day event as retailers open their arms for Americans who prefer to avoid crowds and compare prices online.
Amazon.com, Target, Walmart were all promoting Cyber Week specials in addition to deals exclusive to Cyber Monday.
Shoppers are expected to spend more than $1.5 billion today, up 20 percent from last year, according to research firm comScore. Another prediction from Adobe Digital Index forecasts spending will reach $2 billion, as many shoppers were waiting for today's online deals to make their purchases.
It has already been a big holiday weekend with a record $59.1 billion spent at U.S. stores and websites, according to the National Retail Federation.
Online sales on Thanksgiving Day, traditionally not a popular day for online shopping, rose 32 percent from last year to $633 million, according to comScore. And online sales on Black Friday were up 26 percent from the same day last year, to $1.042 billion. It was the first time online sales on Black Friday surpassed $1 billion.
The National Retail Federation says 247 million shoppers hit stores and websites to cash in on savings during the holiday weekend, up 9 percent from last year. Nearly two-thirds of those shoppers went to stores or hit the web on Black Friday.
Black Friday is now history along with Small Business Saturday. Now, it's Cyber Monday's turn.
On Twitter, retailers were tweeting in full force. Verizon Wireless purchased Twitter's promoted post, #CyberMonday, while Radio Shack marketed a different deal each hour of the day with the hashtag, #24dealsin24. At noon EST, Radio Shack was offering a Tomtom GSP navigator for $99.99 after a discount of 38 percent.
From 9 a.m. to 9 p.m. EST, casual clothing and home retailer Land's End is listing door busters with the hashtag, #LE12HRS.
At midnight, Amazon.com was offering as much as 60 percent off a Panasonic VIERA 55-inch TV that's usually priced higher than $1,000. Sears is offering $430 off a Maytag washer and dryer, each on sale for $399. And Kmart is offering 75 percent off diamond earrings.
"Cyber Monday is really all about doing your homework, and it really means looking for the really good deals," retail analyst Marshal Cohen said. "If it's a really good deal, grab it."
But Cyber Monday might be losing its luster. The busiest day for Internet shopping has been overshadowed this year by online sales that started as early as Thanksgiving Day.
"Look for Cyber Monday to be important, but not necessarily getting that same growth rate that they've had in years past," Cohen said.
The rise in smartphones and tablets has changed consumers' shopping habits since Cyber Monday's inception seven years ago. Cyber Monday was first widely publicized by Shop.org in 2005 to persuade shoppers to buy online, as people were still warming to e-commerce.
"There were so many deals being offered online, starting from Wednesday and all the way through the weekend and now some of the money has already been spent," Cohen said.
Cyber Monday is also an easier alternative for people who don't like long lines and chaos that comes with the Black Friday weekend. This season proved to be no different from past Black Friday horror stories.
A man suspected of shoplifting two DVD players from a Lithonia, Ga., Walmart Sunday died after an altercation with two store employees and a contract security guard.
When officers arrived at the scene, they found the employees on top of the middle-aged man, according to a police report obtained by ABC News affiliate WSB-TV. When an officer bent down to handcuff the suspect, he noticed there was no resistance.
At that point, the officer noticed the suspect was bleeding from the nose and mouth, according to the report. He was transported to DeKalb Medical-Hillandale Hospital, where he was pronounced dead.
"This is truly a sad situation," Dianna Gee, a Walmart spokeswoman, said in a statement issued to ABC News. "We don't know all of the facts right now. We're in the process of working with law enforcement to determine all of the facts and cooperating and providing any information we have to assist in the investigation."
Gee said the contract security guard will no longer be providing services to the retailer. The two store employees have been suspended with pay while Walmart assists police in the investigation.
ABC News' Dan Milano, Alyssa Newcomb, Susanna Kim, ABC News Radio and The Associated Press contributed to this report.