Google announced an
extension to personalized search on Friday. Google noted that they will now provide customized search results based on past search activity for users
not logged into their Google account. Google will set an anonymous cookie in your browser that will store up to 180 days of "signed-out" search activity, including search queries and results you click.
How will you notice the change? Google has been nice enough to place a "View Customization" link on the search results page. Clicking on this link will allow you to see how Google has customized the search results. They will also allow you to disable this customization feature as well. You can also visit the official Google Help and
disable the personalized search.
Danny Sullivan,
Search Engine Land, brings up the point that Google has not provided any information on what percentage of the search results will be personalized listings. Danny brings up the issue of... "If Google rewards the sites you like, does that mean eventually you'll only see stuff you like?". There has been no official word from Google on this.