• by David Goetzl  @dgoetzl, December 7, 2009

PARK CITY, Utah - Amy Piggott is a recent college grad now working for an online marketing company in Utah. The molecular biology graduate is something of an email marketer's dream. A dedicated online shopper, she appreciates e-newsletters about special offers, and even goes to her junk box to retrieve some she has missed.

But she has a gate that must be opened before conducting an e-commerce transaction. There must be no postage fees. "I love free shipping," she said Monday as part of a focus group panel at MediaPost's Email Insider Summit.

It does seem, however, as if marketers are taking heed of people with Piggott's profile this holiday season. A new comScore report shows that during the week of Nov. 22, transactions offering free shipping accounted for 50% of all online sales -- 11% higher than the same week a year ago.

More broadly, online transactions with free shipping as an incentive have been higher than the same period a year ago during each week going back to Nov. 8.

Somewhat surprisingly, however, for the week that included Cyber Monday, the increase was a relatively modest 4%. Data showed that 44% of e-commerce business that week included free shipping deals -- versus 40% in 2008.

It's possible that with so many people shopping on Cyber Monday, marketers dropped the free shipping option, figuring it would not deter customers. With $887 million in online spending on Cyber Monday, the day equaled the most lucrative for e-commerce ever.

ComScore says the most recent data for holiday season spending shows that "the average order value" for purchases with free shipping has been "about 15% higher" than when the customer was on the hook.

Overall, e-commerce spending for the first 34 days of the November-December holiday season has been $15.3 billion, 4% more than a year ago, comScore also reported.