Merchants can benefit from adding social shopping features that let shoppers e-mail friends links to products, write reviews and post product notes on their social networking profiles. These features are especially effective with young shoppers, according to a recent survey from Guidance, which designs and maintains e-stores.

Last week, the National Retail Federation reported that blogging influences 6 percent of the average population's electronics choices and 3.3 percent of their apparel purchases. However, social networking sites themselves remain ineffective for e-commerce. "What sort of shopping opportunities are there in social networks is something that everybody is trying to figure out," LaPierre said, adding that applications PriceGrabber created for Facebook remain dormant. Ackley shares a similar opinion about eBay's Facebook applications. "It's very early days," he said.

Nifty features amount to little in Web stores that go offline under heavy traffic so online merchants must have enough server capacity to handle usage peaks. While sales may remain flat, this holiday season may generate the most e-commerce site traffic ever, said Ken Godskind, chief strategy officer at AlertSite, a vendor of Web performance products.

This is something Google has noticed, since queries related to holiday shopping started appearing earlier than ever this year, McAteer said. "That doesn't mean they were necessarily buying, however," he said.

Thus, merchants must do broad capacity checks for their Web sites, not just for their home pages but also of their shopping cart, search engine, checkout process, product catalog and the like. "It's critical to monitor Web transaction performance for all of the key store processes," Godskind said.

Merchants must have good fraud detection policies and technology, especially this year, when the economic woes might trigger a rise in scams. "In the Christmas rush, everyone is very busy, there's a frantic pace and that's when it's easier to get taken advantage of," said Andre Edelbrock, CEO and co-founder of Ethoca.

"Fraud managers are in a very challenging spot right now," he added. "They're asked to make sure they let every good order through, and quickly, in an environment in which fraud is getting more frequent."

Edelbrock advocates harnessing the power of the merchant community as his company does with its Collaborative Fraud Management platform, to which merchant partners contribute data on good and bad transactions. Ethoca loads that data into a central database and, using algorithms, evaluates individual orders and issues risk assessments on them.

Tony Gao, a marketing professor at Northeastern University's business school, said merchants improve their chances of doing well if they sell essential merchandise, because necessities will be favored over fancy items this holiday season.