Yes Google is bigger but Yahho/Msn has a boat load of visitors/traffic. I would try to take advantage of both and use other networks as well.
Both yahoo and google follow different algorithms to rank the websites.This might be the major reason why some site rank good in one but not in the other.But google is most widely used than yahoo..
I like Google and Yahoo and recently Bing seems to bring in more results that's are not found with Google.
For as traffic wise google get's the most traffic! You want too try and rank your sites for the first page of google for your keyword terms.
Google is better than Yahoo. Both the search engines use different algorithms that is why Page Rank and Keyword rank will be different.
I think Google is better than yahoo. Because Google Search Engine is user friendly search engine, So Google is best Search Engine.
Google is better but Yahoo is not unbest. Both of them are most usarable sites but google is more usarable to the people.
To really answer such a question, who is better, needs to be more defined. if you look at traffic numbers, google, if you look at news reports, I believe yahoo has a gigantic leap, however, tailored down for individual country news, than Google has a more updated quick news delivery. Who is better? McDonalds, BK or Wendys? Who is better BMW, Toyota of Ford? and you can create thousands of challenging questions like this. In our society all have their pace and their followers. Yahoo, with all their turmoil, initial dominance of searches last century (I think), and not defining their directions, still has its place in today's search environment. Don't forget Bing, and then the multitude of small 2nd or 3rd tier search engines, specialized key market SE, they all have a place for the different individuals and users. I believe it is a personal preference who you use and your comfort level. If you are looking at the ad revenues generated, or IM marketing availability of your domain and website, then Google ranking is more a price factor than Yahoo or Bing. The PR and Google analytics have become a stable in marketing the sale of domain and websites, even so, a site can generate more income from other SE. All depends, back to my first sentence, the detailed definition, for which category you ask -who is better?