Consumers in the United States are expected to spend billions of dollars on Cyber Monday -- the Monday after Thanksgiving -- which has become the biggest day for online sales since 2010. This year, online shoppers are expected to spend about 9 percent more than they did last year.

According to research firm comScore, Americans are estimated to spend as much as $2.5 billion on Cyber Monday, after a relatively subdued Thanksgiving week that witnessed fewer shoppers and lower spending compared to last year, The Associated Press (AP) reported, citing the National Retail Federation. According to the NRF, this year’s Thanksgiving week saw 5.3 percent fewer shoppers and 11 percent less spending than 2013. Last year, Cyber Monday generated sales worth $2.29 billion, up 20.6 percent over 2012.

“Online is nowhere near its maturity, so Cyber Monday should be big, with a lot of strength in the days leading up to it,” Sucharita Mulpuru, a Forrester Research analyst, said in a statement. “More consumers are spending more shopping dollars online.”

In the UK, consumers are expected to spend about 650 million pounds ($1.02 billion), a 26 percent increase over last year's Cyber Monday, BBC News reported.

Meanwhile, comScore has predicted that online sales during the November and December shopping season in the U.S. could rise to $61 billion, up 16 percent from last year, while the NRF has forecast that overall holiday sales in the U.S. will increase 4.1 percent to $616.9 billion in 2014.