Google has been experimenting for some time with search engine rankings (SERPS) based on user feedback, preference and prior search history.

Google has made such SERPS available via an OPT-IN to those who have signed up for a Google account and those who use the “search history” function.

Well, now Google will provide user-based SERPS regardless of whether you have signed up or not! According to a blog post yesterday, the future search listings you see will be based on your own data.

In a nutshell, if your past search history suggests that you click on Domino’s Pizza more than Pizza Hut in the listings, then your future searches for “pizza” will likely feature more results from Domino’s.

There are ways to OPT-OUT, but for the casual web surfer it’s complex. To do it you’ll have to clear your cookies (or just not accept the Google cookie) after each browser session.

The end result of this is while Google (as have other search engines) has long been collecting data on its users, now it’s molding that data to show you results that it thinks you want to see. And Google can also add results featuring ads that it thinks you may also like (though they have been doing this for a while by geo-targeting Adwords).

So those fearful of privacy issues on the internet will likely have a field day with this latest announcement as Google continues to stockpile data and personal information on its users.

And one has to wonder, as Google rankings become more and more molded to user tastes and preferences, won’t this kill the idea of actually “searching” for new things?