To understand this, we have to look at why the search engines implemented this new indexing technique.

With the incredible growth of the web, search engines continue to look for, and implement, new and better ways to serve up relevant results while still maintaining a manageable database.

This technological evolution has resulted in the following:

• the use of filters to get rid of duplicate content and invisible text. 
• the importance of META tag indexing (and other tags) being reduced or completely eliminated. 
• the counting of click-thru's 
• link popularity and link quality being added to ranking algorithms

Despite these changes, and there have been many more than those noted above, search engines are still struggling to keep up with web growth and provide relevant results.

Theme indexing takes into account most of what I previously mentioned, but instead of looking at each page as an individual entity, it takes the "theme" of the entire site into account.

An engine that incorporates "themes" into its ranking system, looks at the content as well as the theme of a page, the overall theme of the site, the link popularity of the site, as well as what other sites are "saying" about that particular site. All these factors put together determine the "theme" of the site and page and thereby the ranking of the page in question. The narrower and more focused the theme of a site, the better the site will rank in regards to a matching search term.

Now trust me, this is an extremely simplified description of themes, but my goal here is not to go into the technology behind it but it's impact on search engine optimization and positioning in general.

More and more search engines are incorporating the use of themes to at least some extent into their ranking systems, and because of this, it is crucial that any webmaster who wants to continue to succeed on the internet understand themes and how to use them to his or her advantage.

Quite simply, it means that we have to re-evaluate the way in which we design our sites. The days of the all-purpose site are quickly coming to an end.

Think about it. If you offer a wide range of different products and/or services, when a theme indexing engine visits your site, what will it determine to be the overall theme of your site?

If a visiting engine can't determine a specific theme for your site, you will have little or no hope of coming up well for the search terms you are shooting for.

To thrive in this new world of search engine technology, you must be able to describe the content or "theme" of your site in two words or three at the VERY most.

Can you do that? Can you describe the content of your entire site in two words?

If not, you need to begin re-thinking the focus of your site. You might consider splitting your site into separate sites. Using the same look and feel for each site, only different domains for the different categories of your site. In this way, your visitors will still feel as if they are on the same site, but the engines will see different sites, each with their own "theme".

The next step should be your homepage. The homepage of your site should focus on the overall two word theme of your site. The same two words you used to describe your site. These should be the focus of your homepage.

All of the subpages on your site, should focus on a narrower version of the same theme you targeted on your homepage, using an extension of the same two word description of your site. If your two word description was "computer hardware", then your subpages should focus on keyphrases such as "ibm computer hardware", "toshiba computer hardware" etc.

The key is to always have the same two word description as part of the focus of your subpages. This keeps the overall theme of the site pure and focused, and easily picked up by a visiting engine.

A good example of an implementation of this would be an electronics store. A smart owner of an online electronics store would give each section of his store its own domain name. This could include a domain specifically for cell phones, another for televisions, another for stereos, etc. In doing this, he could then focus individual pages within each domain on specific types of those devices.

Let's look at an example.

Primary domain - www.daves-electronics-store.com 
cell phone domain - www.daves-cell-phones.com
cell phone subpages: nokia-cell-phones.html motorola-cell-phones.html ericcson-cell-phones.html etc.
stereo domain - www.daves-stereos.com  
stereo subpages: panasonic-stereos.html aiwa-stereos.html sony-stereos.html etc. 
televisions domain - www.daves-televisions.com 
televisions subpages: toshiba-televisions.html big-screen-televisions.html sony-televisions.html etc.

As you can see, by using the above technique, you can focus the overall theme of each web site. The cell phone portion of the site may deal with different types of cell phones on each page, but the overall theme is still "cell phones" because this phrase would be found on each and every page.

When dealing with a themes based engine, focus is key. If all other things are equal, the site that is most focused around the specific search term, will come up on top.

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