Keywords are very important if you want your website to reach top levels. But the question arises on how to place these keywords in a site.
For best optimization you can place three phrases or keywords on one page. Beginners should start with one or maybe two keywords. It all depends on the customers you are interacting with. The keywords percentage in the text should generally be from 3 % to 5% of the entire content available on any particular site.
Keywords repetition in keyword tag is a big mistake. It is a quite common practice and should always be avoided. Stop words should never be used in keyword phrases. These words are ignored by the search engines. Few common examples of stop words that are used are the, and, this, because, there and that.
The site’s title and description tag should contain top keywords. But it should not be overloaded with keywords. Engines scan these places first.