The practices came to light following an investigation by antispyware crusader Ben Edelman, a Harvard student who found that the company used a technique known as "cloaking" to dupe search engines into favorably listing decoy Web pages that direct people to other destinations, once they click on the link.
A search Thursday on the term WhenU returned a broken link to a WhenU page on Yahoo and no links to WhenU's pages on Google.
WhenU Chief Executive Avi Naider said the practices in question were the work of an outside search engine optimization firm based in New York. Naider said WhenU will no longer work with the company.
"The moment we were alerted to this today, it was taken down," Naider said, referring to misleading Web pages designed to trick the search engines into giving it higher rankings. "We anticipate being relisted in the major search engines soon."
Google spokesman David Krane confirmed that the site had been pulled. Yahoo could not be immediately reached for comment.
A list of frequently asked questions posted on Google's Web site clearly states that the company prohibits cloaking or any other attempt to manipulate rankings.
"The term 'cloaking' is used to describe a website that returns altered webpages to search engines crawling the site," the posting reads. "To preserve the accuracy and quality of our search results, Google may permanently ban from our index any sites or site authors that engage in cloaking to distort their search rankings."
Outside of the search flap, WhenU is already the subject of a thorny debate over the legality of software used to monitor Web surfing habits and deliver ads--or what's called adware. WhenU, which develops software that sends pop-up and pop-under ads to PCs, is entangled in several lawsuits with companies that claim that its advertisements violate their trademarks and copyrights.
WhenU's desktop software is disseminated with many popular free applications, including the popular file-swapping client Kazaa. It sells ads that can be targeted to people's tastes, thanks to tracking technology that keeps tabs on consumers' Web surfing habits.
Some people consider WhenU's software "spyware," a slippery term that is sometimes used to describe programs that lead to a range of unexpected results for consumers, including surreptitiously installing themselves on a PC, tracking Web-surfing behavior, delivering ads and, in a worst-case scenario, stealing passwords.
WhenU argues that its software is not spyware, because it provides ample disclosure to people who install its application, keeps personal information private and lets people easily uninstall the program.
Last month, WhenU, challenging the constitutionality of a newly enacted law targeting spyware.
WhenU's efforts to manipulate search engine results are aimed to offset negative perceptions about the company, Edelman said.
His investigation found that WhenU created Web pages that borrowed from news articles published by various news Web sites about the company in a bid to drive up its rankings on Google and Yahoo. One such article, published by CNET's News.com, was used to cast a favorable light on WhenU in a court opinion about its pop-up ads. That Web page, among several similar pages, was fed to Google and Yahoo's search crawlers, which are used to index the Web.
Once those pages were indexed and listed in search results for WhenU, the listings were used to redirect people who clicked to other WhenU pages.
"WhenU turned to the Web to try to clean up its image, after facing widespread criticism from consumers, businesses and policy makers. But by resorting to misleading and prohibited methods, WhenU crossed a serious ethical line," Edelman wrote in an e-mail interview.
Edelman has testified in anti-spyware hearings on behalf of companies currently in litigation with adware companies, including WhenU and Gator,. According to a disclosure on his Web site, he has received no compensation for his current investigation into WhenU.