The Internet Library
Picture the Internet as a library, and search engines like Google and Yahoo as the librarians. When you ask one of the librarians to grab you a book on "planting a flower garden," they are going to grab you the best resource they have according to the keywords you used. These advanced librarians take a lot more into account than the old horn-rimmed glasses wearing librarian. Not only do search engines look at the content of your book/website, they may also look at:
- How long people stay on your site
- How many people have viewed your site
- How many referrals or links you have to your site
- When the last time your site was updated
By looking at all of these different criteria, the search engines can provide, with a pretty high success rate, relevant websites on the first page of their results. Remember, the business of the search engines is to provide great results. If you don't get them, you may switch to another provider.
Search engines also take into account the size of your book and the focus of the content. For example, if you want to know how to plant a flower garden you will most likely get websites that deal primarily with flower gardens, or flowers, or gardens. The more concentrated the content, the better chance you'll find exactly what you are looking for.
That is one of the reasons websites that try to provide a lot of information on a lot of different things don't show up very often on the first page of search results. When is the last time you did a search and found a YellowPages.com result on the first page? There are some exceptions. Wikipedia has done an incredible job of becoming one of the biggest resources online. They cover everything from plants to moon rocks, so the specialization theory does not hold true with them. But, in general, if you want to be found in the search engines, do one thing and do it very well.