Google, Yahoo and Bing are still the front runners in the search engine industry. But the combined volume of Yahoo! Search and Bing is less than half the amount of searches conducted at Google. This indicates the importance of Google for search engine optimization.
According to a recent report from Experian Hitwise, during the 4 weeks ending 30th July 2011, a whopping 66.05% of all searches in the US were conducted on Google. Bing and Yahoo! Search together accounted for 28.05% searches (the former accounted for 13.19% searches and later 14.49%).
Apart from these players, the rest of the search engine industry, which is formed by 73 search engines according to Experian, accounts for only about 6% of all searches. The Experian report also states that although the volume of searches was higher at Google, the success rates were higher at Bing and Yahoo! Search. In July 2011, over 81.36% searches conducted at Yahoo! Search led to a website visit, while 68% searches carried out at Google resulted in visit to a site.
The huge different in search volumes perhaps makes the comparison of Google and Yahoo! Search success rates unfair. Sample size is an important consideration when any statistics are considered. Larger sample sizes often result in higher precision. If the amount of searches conducted at both the search engines were comparable, the comparison of their success rates would be fair. But currently the volume of searches conducted at Google is more than double that at Yahoo! Search. In short, Google is still the undisputed king of the search engine industry.