Google Vs Yahoo!
 

In my opinion, it's a great time to do some implementation for Yahoo to get more popularity from SEO!

google vs yahoo
 

There are limited sites of yahoo which we can use for SEO purpose like yahoo answers, but yahoo is not as much helpful as google because the whole world gives priority to google insted of yahoo.

Yahoo has only single technique which helps for SEO is Yahoo Answering.. But it helps a lot in SEO.. As compare to yahoo, Google has many other techniques for SEO..

Yahoo take its search results from Bing so you could optimize for Bing

I think Bing is more suitable customer to try to compete with Google. Yahoo seems to leave the search field. :)

Why you do seo as per the bing search engine. The numbers of visitors come in on googe is more than yahoo and bing search engine. Then do seo as per the google seach engine guidelines.