This link just was recommended by Mike A. from Techcrunch:
http://weblogs.hitwise.com/us-heather-hopkins/2008/02/yahoo_search_draws_younger_aud.html
It shows the cultural and sociological differences between Google and Yahoo users – It shows only differences in USA and Yahoo users are not as rich as Google users. This proves also the fact that Google makes much more money from its traffic through advertisment. Although Yahoo has more traffic on its page. (see also at Alexa - 1.Yahoo 2.Youtube 3. MS Live 4. Google 5. MSM )
In Germany for example nearly nobody uses Yahoo (we google- see Alexa) but in contrast all spanish people I know use Yahoo (update: I checked Alexa, this could no be proved). But I do not think that there is now a corelation between the Techcrunch interpretation (http://www.techcrunch.com/2008/02/16/poor-people-use-yahoo-those-better-off-use-google/), that Yahoo users are poorer than Google Users. Although this could be the fact in the US, I have not the time to proof or disprove this. The Yahoo E-Mail service is much more popular in spain than in Germany. This could also be a reason for the users to choose there start page. By the way AOL was used by a lot of older people as internet provider 5 years ago. Today after the shift to DSL broadband I don’t know anybody who is still using AOL in Germany. Enough statistic speculations for this morning.
Here are some more links around a Google and Yahoo comparison:
http://www.seobook.com/relevancy/
http://googlesystem.blogspot.com/2007/08/differences-between-google-and-yahoo.html
so many different from any search engine because any computer has different IP and that really make different result for search not also yahoo and google, so try you search somethings betwen 2 computer so you’ll get different result i mean like that, sorry my english not good.