Not only can one tell a lot about you by the searches you make, seems a lot can also be deduced from the search engine we use, as a WPP survey of 17,000 US internet users shows -
Ad Age:
What does your search engine say about you? Well, if it's Bing, you're probably an early adopter, but you also visit, shop and ultimately make purchases from Walmart more than other search-engine users. Google searchers, on the other hand, are partial to Target and Amazon, and Yahoo searchers have a strong preference for wireless service from AT&T and Sprint.
Google users are more likely to book a flight online at JetBlue or make a reservation on Hotwire. They are also more likely to do research on a Lexus, while Bing users tend more toward Toyota. Aside from uncovering the research and purchasing habits of consumers, the study claims to have identified a host of demographic and psychographic information on search-engine users.
For instance, AOL customers feel less intellectual than their peers, are 55 and older, spend their money more responsibly, want to blend in to the crowd, feel like they've gotten a raw deal out of life, expect less from their future and, believe it or not, still use dial-up modems. Bing users are middle-aged, highly educated tech-savvy individuals who consider themselves to be average and spend more than 10 hours a week online.
Googlers tend to be the average internet Joe, according to the study. The search leader's loyalists are conventional people yet open to trying new things, believe in following rules and don't consider themselves any smarter or less intelligent than the person next to them. Yahoo users tend to be 55-plus, reserved and a less-independent group with little faith in imagination. They feel they have little control over their future and are skeptical and cautious of new or untried ideas.
Fascinating. I've used Dogpile for nigh on 10 years, it searches all the other engines and aggregates their result for you. I love the "parasite search engine" design (I wonder what that says about me

). Interesting that it hasn't really taken off though.
Update - realised there is a bigger story here. In an age where we see Google moving to mainstream
advertising at the Superbowl (while Pepsi eschews it), clearly which search engine you use is becoming as much a branding battle as for any other commodity product - ie there is little inherent technical differentiation left. Increasingly search engines will try and identify demographics they want for Advertising purposes, and set out their brands to recruit them. Next step is diversofoed brands for different segments - Google Lite, Bing Premier etc - and celebrity sponsorship. Oh joy.....