To increase search engine rank you need to pay attention to many factors. When search engines look at your page, they look at a wide variety of things including not surprisingly the actual content of the main body. One of the key considerations for the search engines is what’s called keyword density. Keyword density refers to the frequency with which a particular keyword or keyword phrase appears on your page relative to the total amount of content.
A keyword could be a single word, or more commonly a short keyword phrase as that’s usually what we’re optimizing for. When that particular word or phrase is typed into the search engine, your page’s density score for that particular keyword is taken into consideration to determine where to rank your page in the results.
This means that for each keyword contained in your page you will have an individual density score with the search engines. It is possible to score well for multiple different phrases, at least on the keyword front. You can increase search engine rank for lots of keywords at once, but while you’re learning it’s probably better to focus on just one or two.
To calculate the density of a keyword within a page, first count the occurrences of the keyword. Then count the total number of words on the page, but rather than counting each individual word you have to count the number of same-length phrases. In other words, if your keyword is three words long, you have to count the number of three-word phrases on the page. Then divide the number of keyword occurrences by the total number of phrases on the page. The resulting percentage is your keyword density.
If you want to increase search engine rank, you’ll want to have a higher density for your keyword than for any other phrase. If this isn’t the case, you should consider rewriting your page and increasing the frequency of use for your keyword. Ideally you’d like to achieve a density of 4-5%.
You don’t want to overdo it. The search engines watch for ‘keyword stuffing’ or blatant keyword spamming, so make sure to keep things reasonable. Use your keyword frequently, but make sure that your page still reads naturally and doesn’t sound forced.