They often only look at the selected keyword phrases that they are paying for, without fully realizing what other residual effects they are receiving.

When a site gets properly optimized, (SEO) it is being transformed into a thought-out navigational pattern to information. This is the same pattern a search engine spider looks for. Don't forget, the easier you make it for a spider to index your site, the better your chances are for getting your site a higher placement in the search engine results page (SERP's).

While W3C validation is something all sites should strive for, it is not required for better rankings. Does it help? Probably. Yahoo engineers have stated that whether a site is W3C compliant or not makes no difference to how it ranks. If it has relevant content, it will get ranked.

Another element when optimizing a site is that through proper naming of page titles, file names and placement of content make the site all the more relevant to the spider. Although Google places less value on Meta Tags, they are still used as part of the algorithm, and should not be overlooked.

After the site has coded properly, the game then goes up to the next level. Search Engine Marketing is used to drive traffic to the site through various means. Press releases, articles, blogs, RSS/XML feeds, Directory Submissions and User Groups all can bring targeted traffic to a site.

Here is where the collateral benefits of SEM begin to appear. Let's say that you have been doing a series of press releases where once a week, you talk about a new color of widget. In each press release you also list the other colors of widgets that you have for sale. Even after only the first release gets sent, you've already created a valuable In-Bound Link to your site for your Red Widget, but since you included the other colors of the widgets as well, they all pick up IBL's as well.

An even greater demonstration of a collateral benefit is ranking for keywords and phrases that you aren't targeting. Keeping to our widget example, if your site copy talks about the different uses of widgets, the available colors that they come in and the best way to preserve your widget, you've just created a multitude of various phrases that your site can get ranked on.

Example site copy:

We sell the highest-quality widget available. Our color selection ranges from red to purple, black to white and can be used in your home or for industrial needs. The widget is the most versatile tool on the market. Pick one up today!

From this one paragraph, here are the possible phrases your site could get ranked on:

?high quality widget

?red widget

?purple widget

?black widget

?white widget

?home widget

?industrial widget

?widget tool

?widget

This is only a tiny sampling of the potential your site has. Remember, each page gets ranked on its own, so that's why it is so important to make sure every page you have on your site is optimized.

Even your contact/about page is critical because if you have a brick-and-mortar business, by listing your street address, you help the search engines geo target your site. Most search engines are already trying to focus your search results regionally. While it's not a major factor yet, it is something to be aware of.

In conclusion, the next time you start checking Google to see where your site ranks for its keyword phrases; don't forget about all of the hidden keywords/phrases that are embedded in your site's copy. You would be surprised at how many of those forgotten about terms end up at the top of the pile....