Page Rank is the number one factor in Google's determination of the search engine ranking of web sites. Page Rank is a numerical figure assigned by Google to expressed the importance, relevance and validity of a website based on the number of links pointing at the website. By determining the volume of links pointing to certain websites, Page Rank attempts to determine that site's importance. However, Page Rank also analyzes the links themselves, and assigns higher importance to links coming from site's that have high Page Rank values themselves. In essence, Page Rank is a complex algorithm that plays a major role in the ranking of web sites on search results pages, and thus catering to Page Rank is a major part in the plans of web optimizers and search engine optimization.
Page Rank assigns different types of links different values, and some receive more attention from search engine crawlers than others. The most valuable type on link in terms of Page Rank is an inbound link. An inbound link is a link that points to your web site only. This link is seen as of the highest importance, because if someone is linking to your content, then it must be valuable.
The other types of link is a reciprocal link, which occurs when one website links to yours, and yours links back to them in turn. Page Rank assigns this link less importance than a one-way inbound link, but it still considers them important. One of the reason reciprocal links have less importance is that reciprocal links are easier to build. When one website links to your homepage and your site links to theirs, it is sometimes seen as a secret handshake, or a "you scratch my back and I'll scratch yours" type of scenario.
However, while some people will tell you that reciprocal links have little value because of this, it's not entirely true. The nature of the internet is built on linking, and when one site links to an important article on yours, and you might later link to an important article on theirs, it doesn't mean your content has little value. In fact, it's the opposite, and the Page Rank crawlers are smart enough to realize this. Therefore, reciprocal links that link between subpages rather than home pages do have value in terms of Page Rank.
However, there are reciprocal links that Page Rank will view as negative. Some webmasters will use Link Farms, which are sites devoted to providing a forum where sites can link between each other as a form of SEO marketing in an attempt to boost Page Rank. Link farms should be avoided, as Page Rank crawlers will pick up on this, and determine those links to be valueless. It's a better idea to focus your search engine marketing on more valuable link building, such as through forums or web directories. For more on Link Building, click here.
Internal linking also plays a big part in SEO for Page Rank purposes. The more links within your site to other pages in your site, the better your Page Rank will be. Therefore, the more internal pages your site has for internal linking, the higher the Page Rank will be. This is why building many pages for specific keywords and linking them to other pages is important.
Optimizing for maximum Page Rank should be a vital part of any SEO strategy. With 80% of internet searches being performed through Google these days, ranking highly on Google is of the utmost importance. Other search engines have algorithms similar to Page Rank, and building links in the correct way will also improve your ranking on those engines as well. But while Page Rank is important, it will be most effective when used in combination with other SEO tools, such as content overhaul for keywords.