After talking to a client today about Search Engine Optimization I went for a browse on the internet to see the percentage of the online search market each of the search engines hold. I had assumed that Google held the largest market share but I was considerably off in my assessment of just how much they held. This link at hitslink (at the time of publication) indicates that Google owns over 85% of the search market share and pulls its data from a pool of 160 million visitors a month and for comparison. Hitwise says Google has just shy of 70% of the market here.
Most of the major search engine companies had been following Google's lead as to ranking techniques for quite a while now (ignoring meta keywords etc.) due to webmasters abusing certain older ranking techniques. Now that real content and actual clicks into your website rank your website on Google, etcetera, instead of hidden words on your web pages and text in the same color as your background: the need for well structured and frequently updated content is paramount.
If you need someone to help you align your content towards drawing more traffic from search engines and to assist Google with tracking clicks through your website please let us know as we'd be glad to help!