Online shopping is gaining at a time when simply filling up a gas tank to head to the mall can seem like a spending spree.

A number of retailers — including Gap, Victoria’s Secret and J. C. Penney — are experiencing double-digit sales growth at their shopping Web sites, creating a surprising bright spot during an otherwise gloomy time for sales in brick-and-mortar stores.

One popular strategy for getting shoppers’ attention is offering free shipping, in contrast to many other businesses, like airlines, that are adding surcharges and other fees to offset their higher costs.

The Web sites of Neiman Marcus, Saks, Nordstrom, Bloomingdale’s, Macy’s, Bon-Ton Stores, Aéropostale, American Eagle Outfitters, Target and Kmart were all offering a deal on shipping this week.

“With gas being such an issue, we know that mall traffic is down more than off-mall traffic,” said Mike Boylson, chief marketing officer for J. C. Penney, which had an 8.7 percent increase in Internet sales in the first quarter of this year.

That is in contrast to a 7.4 percent decrease in sales at stores open at least a year, known as same-store sales and a measure of retail health. “We see more people turning to online because it’s much more efficient in terms of time and money,” Mr. Boylson said.

Retailers are walking a fine line in encouraging online sales. Of course, they are happy to attract more shoppers to their Web sites, but not at the expense of in-store sales — an important measure for investors.

Then again, the Web can drive in-store business, whether shoppers go into a store to return an online purchase or whether they buy an out-of-stock item through a computer at the store.

Lately Nichelle Hines, an actress in Los Angeles, has been shopping online for everything but gas itself — pet supplies, books, DVDs, water filters, kitchen appliances, a dress, her favorite health drink and materials to build a voiceover booth so she does not have to drive to a recording studio.

“It has saved us,” said Ms. Hines, who lives with her boyfriend, Charles, the builder of the booth. “And we really just started doing this three or four months ago just from sheer desperation of spending money on gallons of gas.”

When she does have to drive somewhere, Ms. Hines says she goes online first to note the location of the nearest gas station.

“I’m a computer illiterate person,” she said. “But I’m becoming much more literate as a result of gas prices.”

Victoria’s Secret, too, has had an online sales increase. Its catalog and Internet sales were up 11 percent in the first quarter of this year while same-store sales declined 8 percent, according to Maggie Taylor, vice president, senior credit officer at Moody’s Investors Service.

Excertped from The New York Times online.