The location and frequency of keywords can also help or hurt rankings. Keywords occurring in the Title of the page are given the most relevance. Keywords should appear near the top of the page, because words near the beginning of the document are assumed to be more relevant than words appearing later. Keywords that occur more frequently in the document that other words are given higher relevance. Make sure the keyword text is visible on the page.
Most search engines give high relevance to keywords appearing here.
Plus they represent different phrases for which someone may be searching. Especially use keywords in the Meta tag that don't appear in the text of the page. Otherwise there would be no way for the search engine to index them. Words in the Meta tag can also be used to list synonyms to keywords that appear in the text of the page. Always use the Keyword Meta tag on graphic-intensive pages, since there is less text where keywords can be placed.