The task of keyword targeting your website for natural search results can be a daunting task and if done incorrectly can actually hurt the performance of your site in the search engines. One way keyword targeting can go horribly wrong is when you try to target a laundry list of keywords to one page (many times it’s the homepage) in hopes of getting good positions in the search results. Jamming multiple keyword phrases on one page is called keyword dilution and can cause your site to drop rank in the search engines.
What many people don’t realize is that a major factor that determines the number of keywords that can be targeted on a website is the size of the website. What it boils down to is that you should only be targeting 1 to 2 unique keyword phrases per page. So if your site only has ten pages then the maximum number of unique keyword phrases it can support is 20. And it may even be less then that depending on the competitiveness of the keyword phrase. For example if a keyword phrase that you want your site to show up highly for in the search engines is very competitive, then you will want it to be the only keyword phrase targeted on a single page, at about a 4% keyword density.
But what if there are different variations of a keyword phrase that’s really important to the website? Which variation do you choose? The answer is in finding the balance between popularity and competition of the keywords. That’s were keyword research comes into play. Find out what version of the keyword phrase users are searching for. From there, decide which keyword phrase your site has the best chance of ranking highly for based on the competitiveness of the keyword. Then, according to the number of pages you have on your site choose the number of keywords you will target. If you want to increase that list of keywords, then you will have to create new pages with unique content.