A New Jersey online ad agency claims in a suit filed in federal court in Newark that it was defrauded by artificially generated web traffic on a company's website, an issue e-commerce attorneys said is “extremely prevalent,” but rarely litigated.

In Congoo v. Sell It Social, Congoo LLC, of Somerville, trading as Adiant, is seeking to rescind a one-year contract it signed with Sell It Social, a New York company operating an e-commerce website called Rebel Circus, which sells novelty T-shirts and coffee mugs. Adiant claims Sell It Social is charging it $300,000 in fees based on web traffic counts on the Rebel Circus site that are largely generated by “click farms” or other artificial means.

Adiant concluded that the Rebel Circus site has a “substantial presence” of “fraudulent visitors” based on a count of five clicks per hour on a blank space that the ad agency posted in lieu of advertising, the suit says. Adiant's ads generate 17 clicks per hour from visitors to the Rebel Circus site, according to the complaint. And a “click conversion analysis” showing a statistically low purchase rate further indicates the presence of fraudulent visitors, the suit claims.