So far, U.S. online holiday spending is up 3 percent, according to comScore. That’s a fairly healthy increase, all things considered. As of December 6th, consumers have spent $16 billion online this holiday season. Online sales have dropped off since Thanksgiving and Black Friday’s respective growth of 10 and 11 percent. Cyber Monday sales grew 5 percent year-over-year to $887 million, while the following week's sales fell to 3 percent growth before falling into the negative over the weekend. “After a strong beginning to the week, we saw growth rates decelerate over the weekend to put this past week of holiday shopping in line with our 3 percent growth forecast for the season,” said comScore chairman Gian Fulgoni.

ComScore remains cautiously optimistic about the remainder of the holiday season.

“We are anticipating heavy spending for the current week, making it an important determinant for how the holiday season as a whole will perform," Fulgoni said. "Hopefully, we’ll see a return to the growth rates we observed during the earlier part of this past week and that the weekend softness was just a temporary hiccup."

The report also examines the role of social media in this year’s holiday spending.

Nearly 3 out of 10 respondents (28 percent) say that social media influenced their purchases. While the two most influential social media components were reviews, both professional (11 percent) and consumer generated (11 percent), some of the other responses show the growing power of Facebook and Twitter.

Seven percent of consumers followed companies on Facebook to take advantage of special offers and 5 percent did the same on Twitter (unfortunately, the wording in this category is unclear as to whether or not consumers actually did make purchases based on the offers).

What is interesting is that six percent of consumers made purchases based on friends’ Facebook status updates about a product and 3 percent made a purchase based on a tweet about a product.

But when you think about it, most people weren’t on Twitter last year at this time (a lot of people still weren’t on Facebook), so while the overall influence is low, the overall impact of the service on holiday retail is pretty significant.

By Mark Alvarez