Keyword Density is one of the important On Page SEO factors.It is a value measured in percentage i.e the number of times a keyword displays on a page to the total number of words that appear in a page.For SEO, keyword density is used in order to determine if a web page is relevant to a particular keyword.
However though there are other factors which search engines concentrate on to determine relevancy,keyword density also needs to be given its due importance while performing On Page SEO.

Yahoo follows a different algorithm when compared to the ranking of Google.
Here are some useful tips to improve ranking in Yahoo.

1.Including a listing in yahoo directory is useful.Visit this location https://siteexplorer.search.yahoo.com/submit and submit your site.
2.Submit your website sitemap to Yahoo.If your site has got an XML sitemap,visit the location
https://siteexplorer.search.yahoo.com/submit and enter the URL of sitemap.

Have you ever wondered how to add your business listing to yahoo?Here are a few steps to incorporate it. In order to add business listing,you need to go via local telephone service provider.They usually send their business listings to Yahoo.This needs to be done as one cannot add listings directly to the database.To access InfoUSA, visit dbupdate.infousa.com/dbupdate/yahoo1.jsp

Also note that listings from Info USA are usually updated one to three months.So after submission,you need to wait till your listing shows up in Yahoo Yellow Pages.