Although Black Friday and Cyber Monday are over, people are still hitting the web for holiday gifts.

U.S. Consumers spent nearly $6 billion online for the week ending Dec. 2, according to digital analytics firm comScore. This is a 15 percent increase over last years' total.

Although consumers spent $1.25 billion online on Cyber Monday, sales reached $1.12 billion on Tuesday and $1.03 billion on Wednesday, according to comScore. These days rank as three of the four heaviest online spending days in U.S. history, with Cyber Monday in 2010 also in the ranking.

As the deals from this week expire, it will be important to see the degree to which consumers return to the same retailers to continue their holiday shopping, thereby helping improve retailers' profit margins, or if we experience a pullback in consumer spending..., comScore chairman Gian Fulgoni said in a statement.

Between Nov. 1 and Dec. 2, U.S. consumers spent approximately $18.7 billion online, up from 15 percent last year. This included $479 million in sales on Thanksgiving Day (up 18 percent from 2010), $816 million on Black Friday (up 26 percent) and $1.03 billion on Thanksgiving weekend (up 16 percent).

By the end of the holiday season, comScore expects a 15 percent gain in e-commerce sales compared to a year ago, totaling $37.6 billion.

With the persistent backdrop of macroeconomic uncertainty and continued high unemployment, consumers appear to be increasingly favoring the online benefits of convenience and lower prices, Fulgoni said last month.