Why you only need to optimize your site for 5 Main Search Indexs

According to Nielsen/NetRating study in 2005 here are the top search engines for U.S. users:

1. Google.com 46.2%
2. Yahoo.com 22.5%
3. MSN.com 12.6%
4. AOL.com 5.4% - receives data from Google
   
5. My Way 2.2% - receives data from Ask
   
6. Ask (AskJeeves) 1.6%
7. Netscape.com 1.6% - receives data from Google
   
8. iWon .9% - receives data from Ask
9. EarthLink .8% - receives data from Google and Open directory project
   
10. DogPile .9% - receives data from Google, Yahoo, Msn, and Ask's Meta and directory info.
    
11. Others 5.3%

(This list is search sites popularity not usage of systems or directories) Example AOL and Netscape receive their information from Google's search system.

Since half of the top search engine sites are fed by 5 index systems, you need only worry about:

• Google
• Yahoo
• MSN
• ASK
• DMOZ.com (Open Directory Project)

You may also want to check out (but not necessary):

• Blingo
• MsnSearchAndWin.com
• HotBot
• WebCrawler
• Lycos
• Alexa (powered by Google)
• Amazon a9.com (enhanced by Google)

In short, over half of the search engines out their are powered by another search engine (more often then not Google). Optimize for the primary search engines and you will be set.