A new report out today from ComScore estimates that shoppers will spend approximately $43.4 billion on web-based purchases during November and December. If it holds true, it'll mean that online spending will have increased by 17 percent over last year.

For reference, 2011's online spending was 15 percent higher than it was in 2010. It doesn't take much analysis to see the trend here - something that retail stores are all too familiar with. It's also worth noting that this year's forecast is much higher than the industry's overall retail expectation of a 4.1 percent rise in consumer spending this holiday season.

ComScore chairman Gian Fulgoni said that if the projections hold true, it would put an exclamation point on what has already been a strong year for retail e-commerce. The executive has a fairly optimistic outlook on the season based on the strong lead-up to the 32 shopping days between Thanksgiving and Christmas.

He also believes that consumer confidence and early retailer promotions are serving as wind in the sails for the early part of the holiday season. Convenience, pricing and product selection are all factors that drive consumers to shop online rather than in brick and mortar stores, he said.

According to the research firm, online spending in the first 18 days of the season has already topped 10.1 billion, good for a 16 percent increase over the same time period a year ago. The most successful single day thus far was on November 8 when consumers shelled out $829 million.