The links existing on other websites and pointing to your website are called one way links or back-links. Their number is important for improving your website visibility both for visitors and search engine spiders.

In order to assure a better optimization of the website for the search engine and to increase the traffic, the "quality" of incoming links must be directly proportional with their number. A quality back-link must be present on a website with high rankings in search engines. For example, link farms are not indicated to publish link(s) related to your website.

As a consequence, you should always select popular web directories or forums (they usually have high page ranks) to create back-links to your website. In this way, besides the fact that they will definitely be indexed by search engines before your website, the chances to be on top of the search listings are higher if the forum or web directory has an increased page rank.

The content quality of your website will determine other webmasters to link to articles, news or blogs present on your web pages. The pages containing original content will gain - sooner or later - back-links on similar websites. Press releases and articles related to your website are also indicated to be used in website promotion. If a website provides RSS feeds and they are published as content on other websites, new valuable one way links (back-links) will be created.

The popular social bookmarking directories (like digg.com) are quality websites that can guarantee you better traffic and a visible increase in popularity if users suggest that links from your website be published. If you want to increase the probability of having back links on these websites, various social bookmarking tools should be provided to the users on your web pages.

In any situation, automatic back-links building software should be avoided because search engines could ban your website. Link exchange practice is not recommended either because it will not improve the website rankings (maybe the traffic will be increased). By building back-links with the methods presented in this article, you will always have the guarantee of success in any SEO campaign.