The new tool is called AskEraser. After a user activates it, search requests will vanish from Ask.com's computers within a few hours.
"We definitely want to stand out from the other guys," said Doug Leeds, Ask.com's senior vice president of product management. "This level of control is unprecedented and unmatched."
The company pledged to do this five months ago in response to complaints about how longs its competitors retained search-query information. Google and Microsoft store search engine data for 18 months, while AOL holds onto users' data for 13 months.
But according to web guru Brandon Shalton, Ask.com would have to invert the current search-engine hierarchy for its new policy to have any effect. Ask.com currently only commands 3 percent of search-engine traffic.
"Having your search data purged is probably not a big deal to consumers," said Shalton, who founded the traffic analysis service T3Report.com. "They want search results. And while there are other search engines that might deliver better results, Google is entrenched."
There's also another catch: Ask.com still displays Google-powered text advertisements, which means that some user information will still make its way into Google's databases even with AskEraser turned on.