As gift-buying frenzy mounts in the days before Christmas, US retailers are exporting the country's shopping culture along with once hard-to-get goods to locales around the world.

Spending at US "e-commerce" websites climbed 15 percent from the previous year by the start of December, and online sales on the "Cyber Monday" after Thanksgiving set a new record high of $1.25 billion, according to comScore.

The international share of the Cyber Monday shopping tally climbed to nearly seven percent, the industry tracker reported.

"Black Friday and Cyber Monday are definitely American exports," said Michael DeSimone, chief executive of New York-based FiftyOne Inc., which specializes in helping US store websites handle international transactions.

FiftyOne tends to shipping, tariff, currency exchange and other logistical hassles that discouraged US shops from catering to customers in other countries.

Increasingly, instead of having to travel to the United States for a coveted brand of jeans or t-shirts, people outside the country can simply order online, according to DeSimone.

Sales handled by FiftyOne this holiday season so far have more than doubled from last year.

FiftyOne clients include US retail titans Bloomingdale's, Macy's and Sears, as well as Aeropostale, Barneys New York, Crate & Barrel and online-only "flash sales" sensation Gilt.

Gilt has added tens of thousands of new members since it went international in November with FiftyOne's help, according to Gilt senior director of logistics Crystal Caligiuri.

Gilt sales are modeled after New York City sample sales in which people queue outside shops for chances to buy brand-name products at deeply discounted prices while limited supplies last.

"It's first-come, first-served deals," Caligiuri said. "Whoever clicks on the mouse first gets it."

Since Gilt launched four years ago, it has been flooded with email requests to ship items to Russia, China, South America or elsewhere, but wasn't geared for international sales until November 8.

"We saw a lot of those customers storm in and shop," Caligiuri said. "It's been fun to watch."

US "e-tailers" are indoctrinating international shoppers into this country's rhythm when it comes to bargain hunting and seasonal discounting, according to DeSimone.

"Globalization means that consumers want to have the ultimate retail experience -- which really means having the American retail experience," DeSimone said.

"And consumers know when big buying days in the US are driving sales of the goods they want to purchase, so that also drives international purchasing."

Connecting with global shoppers also causes merchants to adapt to ways things are done in other countries or cultures.

For example, the season in a given hemisphere influences whether winter clothing or beach wear are discounted and US retailers can capitalize on sales pegged to local holidays in other countries.

"The changes in the way we have to think are numerous," Caligiuri said.

"We have to think about how our international customers are similar and how they are different," she continued. "The other important part is making sure the Web experience makes everyone feel comfortable and wanted."

US retailers' savvy regarding online commerce promises to make the array of items available to international shoppers current and varied, and to boost investment in online shopping across the board, according to DeSimone.