Content must be original, to write well, to write marketing information, not pure advertising information. In order to increase the keyword density in the content, you can improve the ranking of the article in the search results. The first paragraph and the end of the content must be added keywords, the middle part of the text should also be reasonable to add keywords, as much as possible to add can ignore the impact of keyword density on the site, so that you do not have to consider, as long as the natural addition, the article can flow. Remember not to pile up keywords.