Choose Your Words Keywords Carefully
Keyword density and placement are important parts of optimizing your articles for search engines. Search engine spiders scan a page in a way that makes it important to place your keywords where they will be detected and recognized as a keyword, so that your article will come up when someone searches for that keyword. Search engine users enter phrases into a search engine to find the information they need. You need to find yourself on top for those keywords. You need to know which keywords people are entering and how to choose the most appropriate ones for your website.
A keyword is a word that is going to be placed in your article several times, not just once as that would make every word a keyword. When a spider sees that you have a word placed several times in an article, it will determine that your page may be useful to users that search for such a keyword.
It is important to note that there is also such a thing as over optimizing your articles for particular words, this is known as, keyword stuffing. When you stuff keywords in an article a spider will detect that you are trying to trick it into placing your article high in the search engine results for that word, and will instead penalize your site and your page for doing such. This may even affect the rankings of your other pages or get your site blacklisted from a particular search engine if you are found keyword stuffing too many times.
The Description tag is not just another place to bulk up on SEO keywords, however. On many search engines, the description tag is what they'll show as your blurb when your website appears on their SERP (Search Engine Results Page). In other words, this may very well be a visitor's first contact with you. The random surfer is more likely to click; a website with a concise, well-written description of the site, that just happens to contain the very keyword he was looking for rather than a description of meaningless jumble of keywords.
No matter what exact density you choose, it is important to place keywords so that there are more at the beginning and end to produce an hour glass effect. Having the right keyword density in your article makes it more likely that you will make money off of that article because it will rise in the search engine results and be seen by more people.
Keyword variation is also needed in making them. People will come up with all sorts of keywords in search of your site. Wrong spelling and capitalization and plural forms of keywords will make your website much easier to find. Longer forms are also needed to be included. The more specific the keyword can get the better chances for your website to be found.
Decide on your most important keyword, and use it at least twice. If you can't figure out how to include that keyword twice and still write an appealing description, then either find someone who can teach you, or hire someone to write the Description tags for you. Choose two or three other keywords that you feel are important, and include them once. Make sure you use standard spelling and grammar; you are basically looking to craft a short but compelling paragraph.
First impressions count and this is your first impression to many, many people browsing search engine results. This is why your Description tag is so important, so write it well! Your SEO will thank you for it.