Two years ago, when Yahoo purchased Alta Vista and thereafter Alltheweb (Fast), it became the world second largest search engine. Many users are quite satisfied with its search result because it is highly relevant. Actually, yahoo did not use search results by Alta Vista or Alltheweb as many people thought. Rather, it invested on a new search technology, called YST (Yahoo Search Technology), a combined outcome of both Alta Vista and Alltheweb.
While Yahoo brings the competition in the search market, it also brings opportunities to those who failed to achieve satisfying traffic from Google search. It is an arena where webmasters can compete for another nearly half internet traffic.
The good news is that to optimize you site for Yahoo is much easier than for Google. It seems that Yahoo is still developing its search technology and the YST currently used is something like the technology Google used several years ago in the regard of search engine optimization. Though Yahoo also puts significant weight on link popularity, it does not disqualify reciprocal links or links from site without relevant content.
Therefore, to obtain targeted search ranking on Yahoo, you only need to make sure your site’s content is highly relevant and outside links are from pages that are indexed by Yahoo. Of course, the text links should contain keywords of your site.