Stuffed Stocking for E-Tailers

ComScore also offered evidence that the strong sales could continue to hit or top peak levels for a few extra days this year because many sites are getting better and delivering on tighter deadlines.

While the strong online revenue is good news for e-tailing giants such as Amazon.com (AMZN Quote) and eBay (EBAY Quote), it may even take some of the edge off disappointing store sales at traditional retailers like Wal-Mart (WMT Quote).

But for Amazon and eBay, the strong season could set these stocks up to catch fire if the companies beat holiday-quarter revenue estimates.

Amazon's stock closed Monday at $39.26, down from the high of $43.25 it hit in the wake of a third-quarter report that was seen as being stronger than expected. Moody's recently upgraded Amazon's corporate family rating to Ba2 from Ba3, citing a stable outlook and its steady business strategy.

But in more recent weeks, Amazon's stock has fallen as low as $37.70, reflecting uncertainty over its sales in the fourth quarter -- by far its busiest. But if ComScore is right that the busy online shopping season may extend a few more days this year, Amazon could be the biggest beneficiary. Thanks to Amazon Prime, shoppers can receive guaranteed two-day shipping from UPS and pay for overnight delivery for only $3.99 a shipment.