To rank well in the search engines, the keywords you target must be carefully picked. If the keywords are too broad (for example “books”, “photos” etc.), your site will have millions of competitors and little chance to rank well. If the keyword phrases are too narrow, few people are likely to search them and find your site. There are also a couple of other factors to consider when using keywords for SEO purposes:
Keyword density: The number of times a keyword or keyword phrase appear in the content of a page. It is calculated by dividing the number of times the keyword is used with the number of words total in the text. If a keyword is used 5 times in a 200 word text, the density would be 2,5%. To calculate the keyword density of a phrase with two or more words, you need to multiply the number of words in the phrase with the number of times it appears. For example, if the phrase “xword yword zword” is used 6 times in a 600 word text, the keyword density would be ((3*6)/600)*100 = 3%. It’s best to focus on just one word or phrase per page, especially for competitive terms. A keyword density of around 2-4% is considered optimal by many. A useful tool to easily calculate the keyword density is the Keyword density analyzer.
Keywords in title and headings: Probably the most important places to put the keywords. Having the right keywords in the title tag will also increase click through rate from the search engines. People are more likely to click a link if the title includes the phrase they have searched for.
Keywords in URL: Most search engines use the keywords in the domain name as part of their ranking formula. Use the domain name to target one or two of your most important keywords.
Keywords in backlinks: Keywords in the anchor text of inbound links is one of the most important factors in ranking well in the search engines. The anchor text should reflect the content of your page and if the links is from a related site, the value of the link will be higher. However, don’t use the exact same keywords on every link. Make sure you vary your anchor links to make them look more natural.
Three Free Keyword Research Tools
Adwords Keyword Tool – Keyword tool from Google. Allows you to type in any word and get a ton of suggestions on synonyms and phrases related to the keyword. It will also give you an estimate on how many searches the keyword gets per month, both globally and by country.
WordStream – A tool that allows you to enter a keyword phrase and get a list of related phrases and keywords. Useful to find new phrases that might not have found otherwise.
SEO Book – Allows you to enter keywords and get an estimate of the daily search volume on Google, Yahoo and Bing.