Google Yahoo Difference

One difference between google and Yahoo search engine rankings is, google mostly goes by the content keyword search where as yahoo is a very reliable search engine to bring traffic on a particular keyword. For example, if you built your site as per yahoo algorithm for a keyword "adsense tips" , then your site gets traffic from google too, as google brings traffic for keywords like "i want adsense tips"
"more adsense earning tips" etc which words may appear in your content, while yahoo brings traffic for the main keyword "adsense tips" if your page is in the first three to 10 ranks. So, optimize your page just picking up possible yahoo keyword which brings traffic, and then fill with content for google. viceversa is not true, as if yahoo has not seen a site and identified the main keyword, you may not get much traffic from it.