U.S. online shoppers spent a record $733 million in a single day on "Cyber Monday," according to market research firm comScore.
Cyber Monday is the first Monday after Thanksgiving and is considered the start of the online holiday shopping season when consumers return to work and seek deals not found in bricks and mortar retailers.
The spend was 21 percent up on the same day last year, according to comScore.
The number of online buyers rose 38 percent from a year ago while the average dollar spend per buyer slipped 12 percent partly due to deep discounting.
ComScore also attributed that decline to a tendency among new Cyber Monday shoppers to spend less than veteran buyers.
The data also showed that 60 percent of the money spent on Cyber Monday came from work computers, comScore said.
The research firm added that 44 percent of Internet users shopped online during Cyber Monday.
The most trafficked sites included those belonging to Amazon.com, Wal-Mart, Target, Dell and Best Buy, comScore said.