The time has passed when people used to search their things on yahoo..... now days google beat all search engines.
Yahoo is more reliable then google while google is the most popular but i prefer google for searching purpose.
I use google for searches and email, i use yahoo when ever i want to find out the latest news. I prefer google
In some countries like Japan and Taiwan, Yahoo is more popular and is commonly used by people as their homepage. That's probably why Yahoo still exists, as well as mail of course, which is probably because a lot of people like me started using Yahoo mail before google existed. Like others have mentioned, Yahoo has made some very bad business decisions over the years. Getting rid of Geocities was bad. Geocities might have evolved into a myspace like system and eventually a facebook like system. Also, Yahoo uses other search tech, not it's own. It even used google as its search system for a while. In markets where Yahoo is popular, people use it for shopping. The average user in Japan and Taiwan, for example, use Yahoo, not ebay or Amazon for shopping.
I stick to Google as an SEO and end user It's going to take light years for Yahoo/Microsoft to catch up to the big G.
Google is the more popular of the search engines so when I'm developing a website I aim my target at Google however I do not forget the others.