Online holiday spending up 15 percent ahead of 'Green Monday'

“These highlights represent another very positive sign for the holiday shopping season, as the week following ‘Cyber Week’ often experiences relative softness in spending momentum due to retailers pulling back on their promotional activity,” said comScore Chairman Gian Fulgoni.

"As we enter what will be the heaviest week of the season for online retailers — beginning with ‘Green Monday’ on December 12 — all signs are now pointing to a strong finish to the season.”

The term Green Monday was coined by eBay in 2007 to describe the Monday around the second week of December that tends to be one of the heaviest online spending days of the year. Fulconi said along with Free Shipping Day — this Friday, Dec. 16 — today will likely see some of the heaviest online sales to date.