To do this, Google has turned to its users to improve search relevance and the overall experience. "We can't go around designing products for the average person," says Sep Kamvar, technical lead for iGoogle. "We have to be taking the person who is doing the searching into account."
Search relevancy hasn't exactly hit a wall. But better search results in the next few years won't come from algorithmic breakthroughs like Google's PageRank, which improves search results by counting Web links as votes of relevance. Rather, it will come from data provided by users.
To encourage users to agree to have their activities tracked, Google has expanded its search history capabilities, giving registered users access to a broader record of their Google-related Web use. Now it's personalizing search results based on the location users designate.
Gathering and storing user data raises all sorts of privacy issues. But Google thinks it has that under control: Personalization is optional and data can be deleted or exported.