Web sites hawking pirated software and other digital goods are luring in about 53 billion visits each year.

That's according to a report (PDF) released yesterday by MarkMonitor, a company that protects online brands for its corporate customers.

Piracy sites made up the majority of the 53 billion visits, while those selling counterfeit goods such as fake prescription drugs and luxury items accounted for a considerably smaller amount of traffic: about 92 million visits a year.

MarkMonitor identified 43 sites as engaging in digital piracy. Among them, three sites--Rapidshare.com, Megavideo.com, and Megaupload.com--accounted for about 21 billion visits per year.

Of course, such sites would argue that they discourage the uploading and sharing of copyrighted material through their respective terms of service. In response to MarkMonitor's findings, RapidShare.com issued the following statement, which it e-mailed to CNET:

"We have read with incomprehension the study of American enterprise brand protection company MarkMonitor which names RapidShare the world's biggest online piracy platform. This defamation of RapidShare as a digital piracy site is absurd and we reserve the right to take legal action against MarkMonitor. RapidShare is a legitimate company that offers its customers fast, simple and secure storage and management of large amounts of data via our servers."

The site also faulted the authors of the MarkMonitor report for concluding that RapidShare is the biggest digital piracy site based on page visits, ignoring the fact that most individual customers and businesses use the site for legitimate reasons to share files with friends and colleagues.

"Of course, that does not mean that we are turning a blind eye to the fact that some people misuse our service to upload copyright-protected works to our servers," RapidShare added. "However, these users are in the absolute minority compared with those who use our services to pursue perfectly legitimate interests. Furthermore, we take a great many steps to prevent and combat copyright infringements"

In other findings, MarkMonitor identified 48 sites as selling counterfeit goods. Of them, 26 sites were found to offer counterfeit prescription drugs and grabbed about 51 million visits each year. Another 21 sites were discovered hawking phony luxury goods and drew in more than 36 million visits per year.

The company conducted the study after discussions with the U.S. Chamber of Commerce.

"Online intellectual property theft--whether it is the sale of counterfeit shoes and fake drugs or the illegal distribution of movies, music, and software--steals jobs, threatens consumers, and hinders our economic growth," Steve Tepp, senior director of Internet counterfeiting and piracy for the Global Intellectual Property Center at the U.S. Chamber of Commerce, said in a statement. "We have known for a long time that rogue websites, those dedicated to piracy and counterfeiting, were flourishing at our expense. Now we begin to see the staggering scope of this problem--more than 53 billion visits on rogue sites."

MarkMonitor conducted its study last year, starting with a sample of 22 brands from such categories as prescription drugs, luxury goods, music, films, and athletic equipment. The company said its automated scans found more than 10,000 suspicious sites that were then filtered to include only dedicated e-commerce and digital content delivery sites. Those sites were ranked by traffic using data from Alexa. MarkMonitor said it then analyzed the sites further to pinpoint the ones that met specific criteria for hawking pirated content or fake goods, which narrowed down the finalists to 90 unique domains.