Despite the economic turmoil, it looks like more people than ever spent the first workday of the holiday season doing something other than work on their computers. Online shoppers spent $846 million in the U.S. on 'Cyber Monday,' according to new comScore Networks data. That was a 15 percent increase over the same day last year.

For the shopping season overall, dating back to Nov. 1, online sales are still down 2 percent, comScore reported this morning.

But the Cyber Monday tally was the second-heaviest online spending day on record. The numbers are a key barometer for Seattle-based Amazon.com and other retailers. The increase suggests that shoppers are responding to the promise of heavy online discounts. Online sales were also up significantly over the post-Thanksgiving weekend, comScore said.

But the increase online may be coming at the expense of traditional retail stores. In its report, comScore cited these findings from its holiday retail survey:

More than half (51 percent) of consumers indicated that the level of promotions and discounts is higher this year than last year, while only 12 percent said that there appeared to be fewer, suggesting that retailers are having to be more aggressive in discounting to spur consumer spending.

Thirty-nine percent of consumers said that there seemed to be fewer people out shopping in retail stores this year than last year, while only 7 percent thought there were more.

Previously: Black Friday online sales up 1%