How is keyword and key phrase position done in situation of Yahoo?
 

Unlike Google, Yahoo is using other algorithms to rank pages on different keywords.
Personally I'm not happy with Yahoo, because he keeps dropped pages on good positions and good websites are thrown back to nowhere and nobody finds them.
In addition, Yahoo is not capable to offer so much traffic for a keyword compared to Google.

From viewpoint of Traffic, you are right because at present Google is the top traffic builder for websites and domains indexed online but Yahoo, although being the second option, is still pretty popular among millions of people worldwide. Naturally, having a fixed position on Yahoo for a competitive business term can mean generating lots of traffic on a daily basis and improving profits of companies in the long term. Yahoo emphasizes usually the materials, contents and keywords appearing on the uploaded website pages.