Coremetrics, Urchin and Whosclickingwho.com are just a few that sell technology to examine click rates and sales that result from paid searches. Alchemist Media, which charges flat fees for its consulting services, has detected fraud while acting as an intermediary between search networks and marketers.
In general, Alchemist's Stricchiola estimates that 10 percent of all search ad sales could be based on fraudulent clicks. But she said the rate can reach 20 percent in particular businesses that have been targeted for click fraud.
Roy de Souza, chief executive of advertising technology firm Zedo, said his company's geotracking systems have traced Internet Protocol addresses to detect click operations in China. In describing one common scheme, he said a legitimate site is duplicated under another name, complete with text ads from a search network. A bot would then be trained to click on the ad links that appear on the bogus site, said de Souza, who estimated that click fraud affects 10 percent to 20 percent of today's search network ads.
Many policing technologies can counter click fraud by analysing Web traffic logs or surfing behaviour. If a page is turned every 1.8 seconds over a period of time, for example, fraud-detecting systems will flag the traffic as suspiciously uniform.
Covert clicks
Human operations can be more difficult to detect because a wide network of people can click on ads from different computers across many regions, without a steady pattern. According to a report in the India Times, residents are being hired to click paid links from home, with the hopes of making between $100 to $200 per month.
In other instances, the source of bogus clicks can be much closer to home.
Joe, the chief executive of an Internet marketing company, enjoys clicking on his rivals' text ads on Google and Yahoo because his competitor must pay as much as $15 each time he does it. Eventually, such phantom clicks can add up and drain a rival's budget.
"It's an entertainment," said the executive, who asked to keep his name and company anonymous. "Why do you run into a store without dropping a quarter in the meter? You know it's wrong, but you do it."
Kevin Lee, chief executive of search marketing firm Did-It, estimates that fraud from such "drive-by" competitive clicks and affiliate scams makes up about 5 percent of the industry's total sales. Lee concedes that he can only guess at the number, but he does know one thing for sure:
If it gets much higher, he said, "then we should all be getting worried."
