E-commerce spending for the holiday shopping season so far has increased 12.9% compared with 2011, comScore Inc. announced this afternoon. Online shoppers in the United States spent approximately $35.0 billion between Nov. 1 and Dec. 16, up from $31.0 billion for the corresponding period last year.

During the week of Dec. 10 to Dec. 16, online shoppers spent just more than $7.0 billion, a record amount for weekly e-commerce sales and a 12% increase from the corresponding period in 2011, the web measurement firm says. ComScore says four days during the week brought in daily e-commerce spending of at least $1 billion.

ComScore has yet to report how much online shoppers spent on Monday, which some call Free Shipping Day, when many retailers offer a last big blast of shipping incentives to encourage late-season purchases.  

“This current week, which kicked off with Free Shipping Day, will be critical in making up some ground on a season-to-date growth rate that remains below initial expectations,” says comScore chairman Gian Fulgoni. “With many retailers extending their free shipping offers into Tuesday and Wednesday of this week, we just may see the sort of late-season jolt needed to push growth rates back into the mid-teens.”

Separately today, the Chase Holiday Pulse, which aggregates payment data from 50 of Chase Paymentech’s largest U.S. web merchants, reported that online sales increased 11.9% between Oct. 29 and Dec. 16 when compared to the corresponding period last year. During the week of Dec. 10 to Dec. 16, those sales increased 10.7% year over year. Consumer electronics sales increased 12.4% year over year, while sales of home goods increased 17.9%.