Online retail spending for the first 31 days of the holiday season starting Nov. 1 fell 2% from a year ago, but spending on Cyber Monday, the Monday after Thanksgiving, rose 15%, according to research company comScore Inc.

The report also said the four days from Black Friday through Cyber Monday saw online sales jump 13%.

“Consumers are clearly responding positively to retailers’ aggressive online discounts,” comScore Chairman Gian Fulgoni said. He added that Monday’s sales of $846 million was the second-highest total for any day since the company started keeping track six years ago.