The majority of web traffic is driven by the major commericial search.

Source - comscore Media Metrix, 2005:

 

Engines – Yahoo!,MSN,Google & askjeeves

(although AOL gets nearly 10% of searches, their engines is powered by goole’s results). If your  site cannot be found by search engines or content cannot be put into their databases, you miss out on the incredible opportunities available to websites provided via search – people who want what you have visiting your site.

Whether your site provides content, services, products or information, search engines are a primary method of navigation for almost all internet users.

Search queries, the world that users type into the search box which contain terms and phrases best suited to your site carry extraordinary value. Experience has shown that search engine traffic can make (or break) an organization’s success. Target visitors to a website can provide publicity. Revenue exposure like no other. Investing in SEO, whether through time or finances, can have an exceptional rat of return.