As of March 2010, Google holds an overwhelming lead over its search engine competitors according to the latest NetMarketShare search engine report. Google commands 85.75% of the worldwide search engine market, an increase in nearly 6% year over year. Yahoo has dropped two percentage points year over year, and is at 5.38%. Bing has been hovering at around the 3% mark. Baidu, which primarily serves the Chinese and Japanese markets has lost a significant share of the market and is currently at 3.52%, while Ask, AOL and other search engines are all around the 1% mark. It’s obvious that all competition has been surrendering market share to Google.

What does this mean in terms of Search Engine Optimization (SEO)? Well, the answer is quite simple, you should primarily focus on optimizing for Google above all others, but don’t forget about Yahoo and Bing, because if the market shifts unexpectedly, it means that you have your bases covered. We all remember when AltaVista was king back in the late 90’s, only to be driven into irrelevancy by its failed portal attempt and the rise of Google. Whatever SEO marketer you choose, make sure they optimize for Yahoo and Bing as well.