US online holiday spending reached $24.8 billion for the first 48 days of the November-December holiday season, a 4% increase over the same period last year, according to comScore.

Much anticipated by retailers, the results of Green Monday spending (Dec. 14) were disappointing overall with sales of $854 million, a 1% drop from last year. However, stronger online sales followed throughout the balance of the week, most notably on Tuesday Dec. 15, which set an individual day spending record of $913 million, the first to surpass the $900 million threshold.

Nine Spending Days Surpass $800 Million

With the heaviest online spending of the season likely behind us, Dec. 15 will rank as the heaviest online spending day of the year at $914 million. Cyber Monday (Nov. 30) follows with $887 million, the highest it has ever ranked on this list.

"In a typical year, Cyber Monday tends to be the eighth to tenth heaviest spending day, but this year it moved higher up the list than ever before," said comScore Chairman Gian Fulgoni. "In part, this is due to the fact that the day fell fairly late in the season, so that pent up consumer demand likely boosted its performance, but also because of the increasing marketing hoopla and promotional activity that surround the day."

The third heaviest spending day of the year was Tuesday, Dec. 1, with $886 million, followed by Wednesday, Dec. 16, with $874 million, and Green Monday (Dec. 14) rounding out the top 5 with $854 million.

Free Shipping Still Strong Incentive

Free shipping has remained an important driver of online shopping throughout the 2009 holiday season. During each week, at least 45% of all transactions included free shipping, outpacing the corresponding week in 2008.The peak occurred during the week ended Dec. 6, with 50% of all transactions including free shipping.

Average order values for online transactions peaked at $117 during the week ended Nov. 29, and the week ended Dec. 6, outpacing the corresponding weeks in 2008.

Free shipping also continued to persuade consumers to spend more per order:

• The average order value for transactions with free shipping was $124 for the week ended Nov. 29, while the average order for those without free shipping was $111.

• For the following week, ended Dec. 6, the average order value for transactions with free shipping was $134 while the average order for those without free shipping was a much lower $103.