Consumers spent more than $1.7 billion (£1.04 billion) online during the biggest-ever Cyber Monday, which was also the "heaviest online spending in history," according to comScore.
Monday's online shopping bonanza saw consumers fork over 18 per cent more in total online spending than they did during last year's Cyber Monday sales period, when they spent roughly $1.5 billion (£915.9 million), the research firm said.
ComScore has been measuring holiday season retail ecommerce spending from desktop computers for the past 32 days, on Tuesday reporting that $23.9 billion (£14.59 billion) was spent online from 1 November through 2 December.
That represents an 8 per cent increase from the same period in 2012, or a 25 per cent jump in spending "using the alternate comparison of the four-week period preceding Thanksgiving," or comparing the 2013 period to 26 October through 26 November last year, according to comScore.
"Any notion that Cyber Monday is declining in importance appears to be completely unfounded as its strong year-over-year growth rate of 18 per cent resulted in yet another record for online spending in a single day," comScore chairman Gian Fulgoni said in a statement.
"While it's true that many retailers are bleeding their Cyber Monday promotions into the weekend before and the days afterward, Cyber Monday itself continues to be the most important day of the online holiday shopping season. That said, we did also see evidence of early promotions pulling some dollars forward into the weekend, so it is possible that Cyber Monday could have even been stronger were it not for the emergence of this trend."
ComScore further broke down some of the online spending data it's compiled for notable shopping days and periods, reporting that $1.2 billion (£739.89 million) was spent on Black Friday (up 15 per cent), and $5.3 billion (£3.24 billion) was spent from Thanksgiving through Cyber Monday (up 22 per cent).
Product categories growing the most year-over-year in terms of online sales in the five-day stretch from Thanksgiving through Cyber Monday were consumer electronics, video game consoles and accessories, home and garden products, apparel and clothing accessories, and sports and fitness goods, in that order, according to comScore.
The research firm said Cyber Monday spending from work computers outstripped spending from home computers for the first time. Some 47.2 per cent of online spending on Cyber Monday in 2012 originated from home PCs, compared with 47.1 per cent from their work desktop computers.
But in 2013, 49.2 per cent of spending came from work computers and just 43.5 per cent originated from home PCs, comScore said. The remaining dollars spent online on Cyber Monday in both 2012 and 2013 originated from international buyers.