There are probably a lot of internet users who have never heard of Ask.com. The search engine site falls well behind other popular search engines like Google and Yahoo. Ask.com announced this week that it will add an additional privacy feature to its search engine called AskEraser.

Though search anonymity is not new, Google and Ask.com will both make search logs anonymous after 18 months, Ask.com will be the first such site to physically erase information about a user's searches from its servers. Data that will be tied to the user-enabled switch includes IP addresses, user IDs, session IDs and the text of their search queries.

Search engines and other websites typically use data gathered from searches and browsing to create profiles to aid in targeting advertisements at users. Without this data, ads delivered to the user may miss their mark, losing revenue for the hosting site.

Privacy advocates don't really have an advertiser's best interests in mind; however, arguing that information gathered by search sites could be used to create personal profiles on users, reflecting everything from their personalities to financial situations. How this information could be used is up to whoever owns it, or possibly whoever steals it.

One caveat to AskEraser is that Ask.com has just signed a five-year agreement with Google to deliver ads alongside Ask.com's search results. The search data will be sent to Google in order to choose relevant ads, and Google is under no obligation to erase the data sent to it, regardless of the user's AskEraser settings.

Most users are not expected to enable the AskEraser feature constantly according to Doug Leeds, senior vice president of Ask.com. Other features offered by the website, such a saved search results, photo albums and blogs will not work if the feature is enabled. In reality, it is likely that only a small portion of Ask.com's users will even bother with the feature.

AskEraser is already available to Ask.com users in the United States and the United Kingdom. The company plans to make the service globally available in 2008.