Online retailers stepped up discounting ahead of the deadline this week for most free shipping of Christmas gifts with guarantee of standard delivery. But they're not panicking — overall, the holiday 2005 shopping season is shaping up well.

Meanwhile, traditional storeowners are waiting for the final shopping week before Christmas to see how their sales turn out.

"This week, consumers can expect to be hearing from retailers reminding them of all the strong promotions that they are offering," said Scott Silverman, executive director of Shop.org, a division of the National Retail Federation in Washington. Online retailers, though, are "going to be pleasantly surprised. The level of optimism is quite high."

• VIDEO: Cyber Sales

Online retailers — like their brick-and-mortar counterparts — jump-started the season with more generous bargains and free shipping than a year ago because of a spike in gasoline prices. But their anxiety has receded along with the price of fuel in recent weeks.

Still, online merchants have increased incentives in the final stretch to seal what they expect will be a strong season. This week, Bluefly.com, which sells discounted designer clothing, is offering an extra 20 percent off each day on different apparel, from sweaters to outerwear. Harryanddavid.com, the gourmet food retailer, is offering a deal where shoppers can buy one item and get the second at half price.

For the 39-day period ended Dec. 9, non-travel spending online surged 23 percent to $12.75 billion from a year ago, according to comScore Networks Inc. That's a bit below the Internet research company's forecast for a 24 percent gain for the season, but comScore Chairman Gian Fulgoni said that this week — the busiest for online retailers — should make up for any shortfall.

While the busiest day for online retailers last year was Dec. 14, Fulgoni expects it may be pushed to Thursday or Friday because of the increasing reliability of online retailers and shoppers' confidence in them.

According to the most recent data from Nielsen/NetRatings Inc., an Internet research firm, online shopping trips to more than 100 e-commerce sites shot up 33 percent for the week ended Dec. 4 from a year ago.

Yahoo! Shopping said Tuesday that traffic has risen from 45 percent to 55 percent since the day after Thanksgiving, beating expectations for growth of 25 percent to 30 percent.

Shipping giants Memphis-based FedEx Corp. (FDX) and Atlanta-based UPS Inc. (UPS) have benefited from the popularity of online shopping, though neither knows for sure how many of those packages are headed to online shoppers.

On what is usually its busiest day of the year, FedEx delivered 8.5 million packages Monday, a 5 percent increase over the same day last year.

Norm Black, spokesman at UPS, said the company is still projecting that it will carry more than 20 million packages on its peak day of Dec. 20. Last year, it projected it would carry about 20 million packages on its peak day, he said.

Meanwhile, on land, stores face more modest gains. According to Michael P. Niemira, chief economist at the International Council of Shopping Centers, sales in November and December for the 75 retailers he tracks will be up anywhere from 3 percent to 3.5 percent on the year. The tally is based on same-store sales, or sales at stores opened at least a year.

While brick and mortar stores depend on the final days before Christmas for sales, online retailers hope to extend their season as well, with many sweetening their shipping offers next week.

Bluefly.com will be offering a free two-day delivery on items ordered from Thursday through next Wednesday.

"We did it last year, but it was a smaller period," said Melissa Payner, CEO of Bluefly.com.