WASHINGTON — One in five bargain hunters shopping for goods online in the U.S. and Europe are duped into buying bogus apparel and luxury goods from counterfeit Web sites, a new MarkMonitor Shopping Report revealed.

This story first appeared in the November 20, 2012 issue of WWD. Subscribe Today.

The MarkMonitor study found that for every shopper looking for fake merchandise online, 20 other shoppers were simply looking for bargains and 20 percent of them mistakenly ended up on counterfeit sites and purchased illegal products.

Underscoring how rampant counterfeiting remains in the U.S., a six-month counterfeit crackdown by U.S. Immigration & Customs Enforcement officials in California’s Orange County, dubbed “Operation Fashion Faux Pas” resulted in nearly $1 million in fake purses, jewelry, sunglasses, cosmetics and perfumes bearing counterfeit trademarks of more than two dozen brands, including Louis Vuitton, Gucci, Rolex, Hermès and Chanel, officials revealed on Friday.

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The stakes are high for apparel and luxury goods brands that stand to lose billions of dollars each year from counterfeits. About 43 percent of people aged 16 to 74 in the European Union made a purchase on the Internet, while shoppers in the U.K., Germany and France recorded much higher rates of online purchases, according to Eurostat. In the U.S., the average shopper will spend $419 online this holiday season, a 12 percent increase from last year, according to Forrester Research, as cited in the study.

MarkMonitor, an intellectual property and science business that is part of Thomson Reuters, worked with Nielsen’s online panelists in six countries over a nine-month period analyzing some 8,000 Web sites selling legitimate products and 1,000 selling counterfeit goods. Analysts monitored 5 million shopping “sessions” online and focused on search terms that shoppers used such as “fake,” “replica,” “cheap” or “discount” to determine what motivates shoppers when making online purchases.

“Consumers are being waylaid by rogue e-commerce sites, causing brands to lose business,” said Fredrick Felman, chief marketing officer of MarkMonitor. “The findings from our Shopping Report underscore the importance of developing proactive protection strategies in the digital age.”

The study charged that Italian and French online shoppers are “three to five times more likely than Swiss and German online shoppers to visit counterfeit sites.”

Researchers advised brands to buy terms like “discount” outlet or other bargain-related terms and registering domain names with the terms to ensure that potential customers find their sites.