Keyword Strategy
Keyword frequency
Frequency is the number of times your keyword is used in the analysed area of the page.
Example: If the page's first heading is 'Get the best XYZ services provided by XYZ Company', frequency of keyword 'XYZ' in the heading will be two. Frequency relates only to the exact matches of a keyword. Therefore, frequency of key phrase 'XYZ services' will be one, because as exact match, this keyword is used only once.
Search engines use frequency as a measure of keyword importance.
Search engines rate pages with more keywords as more relevant results, and score them higher. However, you should not use too many keywords, since most search engines will penalise you for this practice for being seen as an attempt to artificially inflate rankings.
Keyword weight (density)
Keyword weight is a measure of how often a keyword is found in a specific area of the Web page like a title, heading, anchor name, visible text, etc. Unlike keyword frequency, which is just a count, keyword weight is a ratio.
Keyword weight will depend on the type of keyword, that is if the keyword is a single word or phrase. If the keyword includes two or more words, for example, 'XYZ services', every word in the key phrase (i.e. both 'XYZ' and 'services') contributes to the weight ratio in the weight formula, and not as one keyword ('XYZ services').
Keyword weight is calculated as the number of words in the key phrase multiplied by frequency and divided by the total number of words (including the keyword).
Example: The title of a Web page is 'Get Best XYZ Services'. Keyword weight for 'XYZ services' is 2*1/4*100%=50%. If you reduce the number of words in the title by removing the word 'get', so the title becomes 'Best XYZ Services', than the keyword weight will be larger: 2*1/3*100%=67%. Finally, if you only keep 'XYZ Services' in the title, the keyword weight will become 100% -- 2*1/2*100%.
So, to increase the keyword weight, you should either add some more keywords or reduce the number of words in the page area. The proportion of the keywords to all words will become larger, so will the keyword weight.
Many search engines calculate keyword weight when they rank pages for a particular keyword. Normally, high keyword weight tell search engines that the keyword is extremely important in the text; however, a weight that is too high can make search engines suspect you of spamming and they will penalise your website's rankings.
Keyword Prominence
Prominence is another measure of keyword importance that relates to the proximity of a keyword to the beginning of the analysed page area. Being the keyword that is used at the beginning of the Title, Heading, or on top of the visible text of the page is considered more important than other words. Prominence is a ratio that is calculated separately for each important page area such as a title, headings, visible text, anchor tags, etc.
HTML pages are written in a document-like fashion. The most important items of a document's visible text are placed at the top, and their importance is gradually reduced towards the bottom. This idea can be also applied to keyword prominence. Normally, the closer a keyword to the top of a page and to the beginning of a sentence, the higher its prominence is. However, search engines also check if the keyword is present in the middle and at the bottom of the page, so you should place some keywords there too.
The prominence formula takes the following factors into account:
1) Keyword positions in the area,
2) Number of words in the keyword, and
3) Total number of words in the area.
100% prominence is given to a keyword or keyphrase that appears at the beginning of the analyzed page area. Example 1: Let's take the page title 'Daily horoscopes on your desktop' and analyze prominence of keyphrase 'daily horoscopes'. The title word order will be:
'Keyword1, keyword2, word3, word4, word5'. Prominence will be 100% here as the keyphrase is present at the beginning of the sentence.
The keyword/keyphrase in the middle of the analyzed area will have 50% prominence.
Example 2: The anchor name is 'Find here the daily horoscope for your sign'. The keyword prominence of the phrase 'daily horoscope' in this case will be 50% as the keyphrase is located in the middle of the sentence -- 'Word1, word2, word3, keyword4, keyword5, word6, word7, word8'.
As a keyword appears further back in the area, its prominence will be counted from zero and it will depend on how close to the end it is. If the keyword appears at the end of the area, its prominence will be close to 0%. If the keyword appears at the beginning of the area and then is repeated in the middle or at the end, its prominence will be 100% because prominence of the fist used keyword prevails over the repeated keywords.
Keyword in URL
Having keyword in your domain name and/or folder names and file names increases your chances to gain top positions for these keywords. If you aren't a brand-oriented business, it is recommended that you purchase the domain name that contains your keyword. If your keyphrase consists of more than one keyword, the best way to separate them in the URL is with a hyphen "-":
If it seems impossible to get such a domain name, or your site is already well established over a keyword-poor domain, attempt to compensate it by using keywords in folder and file names of your site's file system on the server.